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1.  Inter- and Intra-Individual Variation in Allele-Specific DNA Methylation and Gene Expression in Children Conceived using Assisted Reproductive Technology 
PLoS Genetics  2010;6(7):e1001033.
Epidemiological studies have reported a higher incidence of rare disorders involving imprinted genes among children conceived using assisted reproductive technology (ART), suggesting that ART procedures may be disruptive to imprinted gene methylation patterns. We examined intra- and inter-individual variation in DNA methylation at the differentially methylated regions (DMRs) of the IGF2/H19 and IGF2R loci in a population of children conceived in vitro or in vivo. We found substantial variation in allele-specific methylation at both loci in both groups. Aberrant methylation of the maternal IGF2/H19 DMR was more common in the in vitro group, and the overall variance was also significantly greater in the in vitro group. We estimated the number of trophoblast stem cells in each group based on approximation of the variance of the binomial distribution of IGF2/H19 methylation ratios, as well as the distribution of X chromosome inactivation scores in placenta. Both of these independent measures indicated that placentas of the in vitro group were derived from fewer stem cells than the in vivo conceived group. Both IGF2 and H19 mRNAs were significantly lower in placenta from the in vitro group. Although average birth weight was lower in the in vitro group, we found no correlation between birth weight and IGF2 or IGF2R transcript levels or the ratio of IGF2/IGF2R transcript levels. Our results show that in vitro conception is associated with aberrant methylation patterns at the IGF2/H19 locus. However, very little of the inter- or intra-individual variation in H19 or IGF2 mRNA levels can be explained by differences in maternal DMR DNA methylation, in contrast to the expectations of current transcriptional imprinting models. Extraembryonic tissues of embryos cultured in vitro appear to be derived from fewer trophoblast stem cells. It is possible that this developmental difference has an effect on placental and fetal growth.
Author Summary
We have screened a population of children conceived in vitro for epigenetic alterations at two loci that carry parent-of-origin specific methylation marks. We made the observation that epigenetic variability was greater in extraembryonic tissues than embryonic tissues in both groups, as has also been demonstrated in the mouse. The greater level of intra-individual variation in extraembryonic tissues of the in vitro group appears to result from these embryos having fewer trophoblast stem cells. We also made the unexpected observation that variability in parental origin-dependent epigenetic marking was poorly correlated with gene expression. In fact, there is such a high level of inter-individual variation in IGF2 transcript level that the presumed half-fold reduction in IGF2 mRNA accounted for by proper transcriptional imprinting versus complete loss of imprinting would account for less than 5% of the total population variance. Given this level of variability in the expression of an imprinted gene, the presumed operation of “parental conflict” as the selective force acting to maintain imprinted gene expression at the IGF2/H19 locus in the human should be revisited.
doi:10.1371/journal.pgen.1001033
PMCID: PMC2908687  PMID: 20661447
2.  Methylation levels at imprinting control regions are not altered with ovulation induction or in vitro fertilization in a birth cohort 
Human Reproduction (Oxford, England)  2012;27(7):2208-2216.
STUDY QUESTION
Do fertility treatments, including ovulation induction (OI), alter epigenetic mechanisms such as DNA methylation at imprinted loci?
SUMMARY ANSWER
We observed small but statistically significant differences in certain imprinting control regions (ICRs) based on the method of conception, however, these small changes in methylation did not correlate to the overall transcriptional levels of the genes adjacent to the ICRs (such as KCNQ1 and SNRPN).
WHAT IS KNOWN AND WHAT THIS PAPER ADDS
Assisted reproductive technology (ART) has been associated with an increase in the risk of rare childhood disorders caused by loss of imprinting (LOI). This study provides novel epigenetic analyses on infants conceived by OI and examines how methylation levels correlate with gene expression.
DESIGN
Data and biospecimens used in this study were from 147 participants of the Epigenetic Birth Cohort comprising 1941 mother–child dyads recruited between June 2007 and June 2009 at the Department of Obstetrics, Gynecology and Reproductive Biology at Brigham and Women's Hospital (BWH) in Boston, MA, USA. Wilcoxon rank-sum tests were used to examine the differences in median percent methylation at each differentially methylated region (DMR) between the spontaneous conception control group and the fertility treatment groups (OI and IVF).
PARTICIPANTS AND SETTING
For each woman who reported IVF we selected a woman who conceived spontaneously matched on age (±2 years). To increase efficiency, we matched the same controls from the spontaneously conceived group to participants who reported OI. If an appropriate control was not identified that had been previously matched to an IVF participant, a new control was selected. The final analytic sample consisted of 61 spontaneous, 59 IVF and 27 OI conceptions.
MAIN RESULTS AND THE ROLE OF CHANCE
No functionally relevant differences in methylation levels were observed across five (out of six) imprinted DMRs in either the placenta or cord blood of infants conceived with OI or IVF compared with infants conceived spontaneously. While KCNQ1, SNRPN and H19 DMRs demonstrated small but statistically significant differences in methylation based on the method of conception, expression levels of the genes related to these control regions only correlated with the methylation levels of H19.
BIAS, CONFOUNDING AND OTHER REASONS FOR CAUTION
Limitations of our study include the limited sample size, lack of information on OI medication used and culture medium for the IVF procedures and underlying reasons for infertility among OI and IVF patients. We did not perform allele-specific expression analyses and therefore cannot make any inferences about LOI.
GENERALIZABILITY TO OTHER POPULATIONS
These results are likely to be generalizable to non-Hispanic white individuals in populations with similar ART and fertility treatments.
STUDY FUNDING/COMPETING INTEREST(S)
This project was supported by the Milton Fund, Harvard University (P.I.: K.B.M) and by Public Health Research Grant 5R21CA128382 from the National Cancer Institute, National Institutes of Health (P.I.: K.B.M.). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. No conflict of interests to declare.
Trial registration number
N/A.
doi:10.1093/humrep/des151
PMCID: PMC3376159  PMID: 22587996
ovulation induction; IVF; DNA methylation; genomic imprinting; fertility treatment
3.  Study of DNA methylation patterns of imprinted genes in children born after assisted reproductive technologies reveals no imprinting errors: A pilot study 
Assisted reproductive technology (ART) including in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) have been shown to be associated with abnormal genomic imprinting, thus increasing the incidence of imprinting disorders such as Beckwith-Wiedemann syndrome (BWS) and Angelman syndrome (AS) in ART-conceived children. Furthermore, a recent study described abnormal DNA methylation in clinically normal children conceived by ART. However, data from different studies are conflicting or inconclusive. This study examined DNA methylation patterns of multiple imprinted genes in children born after ART to primarily evaluate the impact of ART on genomic imprinting. A total of 101 newborns conceived by ART (40 ICSI and 61 IVF) and 60 naturally conceived newborns were involved in our study. After obtaining the approval of the Institutional Ethics Committee, umbilical cord blood was collected from each infant. Genomic DNA was isolated from each blood sample and treated using sodium bisulfite. Subsequently, using methylation-specific PCR (MS-PCR), we analyzed six differentially methylated regions (DMRs) including KvDMR1, SNRPN, MEST, MEG3, TNDM and XIST. Meanwhile, information regarding twin pregnancies, gestational age, and birth weight of the neonates was documented. None of the cases presented with phenotypic abnormalities. Children conceived by ART were more likely to have low birth weight and to be born before term, compared with children conceived spontaneously. However, 7 months to 3 years of clinical follow-up showed that none of the children had clinical symptoms of any imprinting diseases. Furthermore, the MS-PCR results showed that all 161 children had normal DNA methylation patterns at six DMRs despite the different mode of conception. Our data did not indicate a higher risk of DNA-methylation defects in children born after ART. However, further studies using quantitative methods are needed to confirm these results.
doi:10.3892/etm.2011.261
PMCID: PMC3440701  PMID: 22977570
assisted reproductive technology; genomic imprinting; imprinting disorder; DNA methylation
4.  Silver–Russell Syndrome Due to Paternal H19/IGF2 Hypomethylation in a Twin Girl Born After In Vitro Fertilization 
Silver–Russell syndrome (SRS) is a clinically and genetically heterogeneous syndrome characterized by severe intrauterine and postnatal growth retardation, facial dysmorphism and body asymmetry. One of the main molecular mechanisms leading to the syndrome involves methylation abnormalities of chromosome 11p15. In the last decades, an increase of imprinting disorders have been reported in children born from assisted reproductive technology (ART); however there is currently little evidence linking SRS and ART. Only few infants with SRS born using ART, supported by molecular analysis, have been described. We report on a twin-girl conceived using intracytoplasmic sperm injection (ICSI) diagnosed with SRS. Molecular studies revealed a hypomethylation of the paternal H19/IGF2 Imprinting Control Region. Her twin sister had a normal prenatal and postnatal growth and a normal methylation pattern of the chromosome 11p15. This is the second reported case of a twin infant with SRS conceived using ART with hypomethylation of H19/IGF2; it provides additional evidence of a possible relationship between ART procedures and methylation defects observed in SRS. Given the clinical heterogeneity of SRS, and the increased risk of multiple and preterm births in the ART-conceived children, it is possible that a number of cases of SRS remains undiagnosed in this population. Future studies should investigate the possible link between ART and SRS, in order to better understand the causes of epimutations in ART pregnancies, and to help clinicians to adequately counsel parents who approach to ART and to assess the opportunity of a long-term follow-up of children conceived using ART. © 2013 Wiley Periodicals, Inc.
doi:10.1002/ajmg.a.36145
PMCID: PMC4065345  PMID: 24038823
Silver–Russell syndrome; in vitro fertilization; imprinting disorders
5.  Epimutation profiling in Beckwith-Wiedemann syndrome: relationship with assisted reproductive technology 
Clinical Epigenetics  2013;5(1):23.
Background
Beckwith-Wiedemann syndrome (BWS) is a congenital overgrowth disorder associated with abnormalities in 11p15.5 imprinted genes. The most common cause is loss of methylation (epimutation) at the imprinting control centre 2 (IC2/KvDMR1). Most IC2 epimutations occur sporadically but an association with conception after assisted reproductive technologies (ART) has been reported. A subgroup of IC2 epimutation cases also harbour epimutations at other imprinting centres (ICs) outside of 11p15.5. We have investigated the relationship between these multiple epimutation cases (ME+), history of ART and clinical phenotype in a cohort of 187 BWS IC2 epimutation patients.
Results
Methylation analysis at PLAGL1, MEST and IGF2R ICs demonstrated an over-representation of patients with abnormally low methylation (8.5%, 12% and 6% respectively). At IGF2R some patients (2%) had gain of methylation but this was also detected in controls. Though there were no significant correlations between the methylation index (MIs) at the three ICs tested, a subset of patients appeared to be susceptible to multiple epimutations (ME+) and 21.2% of ME + patients had been conceived by ART compared to 4.5% (P = 0.0033) without additional epimutations. Methylation array profiling (Illumina Goldengate®) of patients and controls (excluding 11p15.5 loci) demonstrated significant differences between patients and controls. No significant associations were found between aspects of the BWS phenotype and individual epimutations but we describe a case presenting with a post-ART BWS-like phenotype in which molecular analysis demonstrated loss of paternal allele methylation at the 11p15.5 IC1 locus (IC1 regulates imprinting of IGF2 and H19). Loss of paternal allele methylation at the IC1 is the molecular finding associated with Silver-Russell syndrome whereas BWS is associated with gain of maternal allele methylation at IC1. Further analysis demonstrated epimutations at PLAGL1 and MEST consistent with the hypothesis that the presence of multiple epimutations may be of clinical relevance.
Conclusions
These findings suggest that the ME + subgroup of BWS patients are preferentially, but not exclusively, associated with a history of ART and that, though at present, there are no clear epigenotype-phenotype correlations for ME + BWS patients, non-11p15.5 IC epimutations can influence clinical phenotype.
doi:10.1186/1868-7083-5-23
PMCID: PMC3878854  PMID: 24325814
Beckwith-Wiedemann syndrome; Assisted reproductive technology; Imprinting; Genetics
6.  In Vitro Fertilization and Multiple Pregnancies 
Executive Summary
Objective
The objective of this health technology policy assessment was to determine the clinical effectiveness and cost-effectiveness of IVF for infertility treatment, as well as the role of IVF in reducing the rate of multiple pregnancies.
Clinical Need: Target Population and Condition
Typically defined as a failure to conceive after a year of regular unprotected intercourse, infertility affects 8% to 16% of reproductive age couples. The condition can be caused by disruptions at various steps of the reproductive process. Major causes of infertility include abnormalities of sperm, tubal obstruction, endometriosis, ovulatory disorder, and idiopathic infertility. Depending on the cause and patient characteristics, management options range from pharmacologic treatment to more advanced techniques referred to as assisted reproductive technologies (ART). ART include IVF and IVF-related procedures such as intra-cytoplasmic sperm injection (ICSI) and, according to some definitions, intra-uterine insemination (IUI), also known as artificial insemination. Almost invariably, an initial step in ART is controlled ovarian stimulation (COS), which leads to a significantly higher rate of multiple pregnancies after ART compared with that following natural conception. Multiple pregnancies are associated with a broad range of negative consequences for both mother and fetuses. Maternal complications include increased risk of pregnancy-induced hypertension, pre-eclampsia, polyhydramnios, gestational diabetes, fetal malpresentation requiring Caesarean section, postpartum haemorrhage, and postpartum depression. Babies from multiple pregnancies are at a significantly higher risk of early death, prematurity, and low birth weight, as well as mental and physical disabilities related to prematurity. Increased maternal and fetal morbidity leads to higher perinatal and neonatal costs of multiple pregnancies, as well as subsequent lifelong costs due to disabilities and an increased need for medical and social support.
The Technology Being Reviewed
IVF was first developed as a method to overcome bilateral Fallopian tube obstruction. The procedure includes several steps: (1) the woman’s egg is retrieved from the ovaries; (2) exposed to sperm outside the body and fertilized; (3) the embryo(s) is cultured for 3 to 5 days; and (4) is transferred back to the uterus. IFV is considered to be one of the most effective treatments for infertility today. According to data from the Canadian Assisted Reproductive Technology Registry, the average live birth rate after IVF in Canada is around 30%, but there is considerable variation in the age of the mother and primary cause of infertility.
An important advantage of IVF is that it allows for the control of the number of embryos transferred. An elective single embryo transfer in IVF cycles adopted in many European countries was shown to significantly reduce the risk of multiple pregnancies while maintaining acceptable birth rates. However, when number of embryos transferred is not limited, the rate of IVF-associated multiple pregnancies is similar to that of other treatments involving ovarian stimulation. The practice of multiple embryo transfer in IVF is often the result of pressures to increase success rates due to the high costs of the procedure. The average rate of multiple pregnancies resulting from IVF in Canada is currently around 30%.
An alternative to IVF is IUI. In spite of reported lower success rates of IUI (pregnancy rates per cycle range from 8.7% to 17.1%) it is generally attempted before IVF due to its lower invasiveness and cost.
Two major drawbacks of IUI are that it cannot be used in cases of bilateral tubal obstruction and it does not allow much control over the risk of multiple pregnancies compared with IVF. The rate of multiple pregnancies after IUI with COS is estimated to be about 21% to 29%.
Ontario Health Insurance Plan Coverage
Currently, the Ontario Health Insurance Plan covers the cost of IVF for women with bilaterally blocked Fallopian tubes only, in which case it is funded for 3 cycles, excluding the cost of drugs. The cost of IUI is covered except for preparation of the sperm and drugs used for COS.
Diffusion of Technology
According to Canadian Assisted Reproductive Technology Registry data, in 2004 there were 25 infertility clinics across Canada offering IVF and 7,619 IVF cycles performed. In Ontario, there are 13 infertility clinics with about 4,300 IVF cycles performed annually.
Literature Review
Royal Commission Report on Reproductive Technologies
The 1993 release of the Royal Commission report on reproductive technologies, Proceed With Care, resulted in the withdrawal of most IVF funding in Ontario, where prior to 1994 IVF was fully funded. Recommendations of the Commission to withdraw IVF funding were largely based on findings of the systematic review of randomized controlled trials (RCTs) published before 1990. The review showed IVF effectiveness only in cases of bilateral tubal obstruction. As for nontubal causes of infertility, there was not enough evidence to establish whether IVF was effective or not.
Since the field of reproductive technology is constantly evolving, there have been several changes since the publication of the Royal Commission report. These changes include: increased success rates of IVF; introduction of ICSI in the early 1990’s as a treatment for male factor infertility; and improved embryo implantation rates allowing for the transfer of a single embryo to avoid multiple pregnancies after IVF.
Studies After the Royal Commission Report: Review Strategy
Three separate literature reviews were conducted in the following areas: clinical effectiveness of IVF, cost-effectiveness of IVF, and outcomes of single embryo transfer (SET) in IVF cycles.
Clinical effectiveness of IVF: RCTs or meta-analyses of RCTs that compared live birth rates after IVF versus alternative treatments, where the cause of infertility was clearly stated or it was possible to stratify the outcome by the cause of infertility.
Cost effectiveness of IVF: All relevant economic studies comparing IVF to alternative methods of treatment were reviewed
Outcomes of IVF with SET: RCTs or meta-analyses of RCTs that compared live birth rates and multiple birth rates associated with transfer of single versus double embryos.
OVID MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Cochrane Library, the International Agency for Health Technology Assessment database, and websites of other health technology assessment agencies were searched using specific subject headings and keywords to identify relevant studies.
Summary of Findings
Comparative Clinical Effectiveness of IVF
Overall, there is a lack of well composed RCTs in this area and considerable diversity in both definition and measurement of outcomes exists between trials. Many studies used fertility or pregnancy rates instead of live birth rates. Moreover, the denominator for rate calculation varied from study to study (e.g. rates were calculated per cycle started, per cycle completed, per couple, etc...).
Nevertheless, few studies of sufficient quality were identified and categorized by the cause of infertility and existing alternatives to IVF. The following are the key findings:
A 2005 meta-analysis demonstrated that, in patients with idiopathic infertility, IVF was clearly superior to expectant management, but there were no statistically significant differences in live birth rates between IVF and IUI, nor between IVF and gamete-intra-Fallopian transfer.
A subset of data from a 2000 study showed no significant differences in pregnancy rates between IVF and IUI for moderate male factor infertility.
In patients with moderate male factor infertility, standard IVF was also compared with ICSI in a 2002 meta-analysis. All studies included in the meta-analysis showed superior fertilization rates with ICSI, and the pooled risk ratio for oocyte fertilization was 1.9 (95% Confidence Interval 1.4-2.5) in favour of ICSI. Two other RCTs in this area published after the 2002 meta-analysis had similar results and further confirmed these findings. There were no RCTs comparing IVF with ICSI in patients with severe male factor infertility, mainly because based on the expert opinion, ICSI might only be an effective treatment for severe male factor infertility.
Cost-Effectiveness of IVF
Five economic evaluations of IVF were found, including one comprehensive systematic review of 57 health economic studies. The studies compared cost-effectiveness of IVF with a number of alternatives such as observation, ovarian stimulation, IUI, tubal surgery, varicocelectomy, etc... The cost-effectiveness of IVF was analyzed separately for different types of infertility. Most of the reviewed studies concluded that due to the high cost, IVF has a less favourable cost-effectiveness profile compared with alternative treatment options. Therefore, IVF was not recommended as the first line of treatment in the majority of cases. The only two exceptions were bilateral tubal obstruction and severe male factor infertility, where an immediate offer of IVF/ICSI might the most cost-effective option.
Clinical Outcomes After Single Versus Double Embryo Transfer Strategies of IVF
Since the SET strategy has been more widely adopted in Europe, all RCT outcomes of SET were conducted in European countries. The major study in this area was a large 2005 meta-analysis, followed by two other published RCTs.
All of these studies reached similar conclusions:
Although a single SET cycle results in lower birth rates than a single double embryo transfer (DET) cycle, the cumulative birth rate after 2 cycles of SET (fresh + frozen-thawed embryos) was comparable to the birth rate after a single DET cycle (~40%).
SET was associated with a significant reduction in multiple births compared with DET (0.8% vs. 33.1% respectively in the largest RCT).
Most trials on SET included women younger than 36 years old with a sufficient number of embryos available for transfer that allowed for selection of the top quality embryo(s). A 2006 RCT, however, compared SET and DET strategies in an unselected group of patients without restrictions on the woman’s age or embryo quality. This study demonstrated that SET could be applied to older women.
Estimate of the Target Population
Based on results of the literature review and consultations with experts, four categories of infertile patients who may benefit from increased access to IVF/ICSI were identified:
Patients with severe male factor infertility, where IVF should be offered in conjunction with ICSI;
Infertile women with serious medical contraindications to multiple pregnancy, who should be offered IVF-SET;
Infertile patients who want to avoid the risk of multiple pregnancy and thus opt for IVF-SET; and
Patients who failed treatment with IUI and wish to try IVF.
Since, however, the latter indication does not reflect any new advances in IVF technology that would alter existing policy, it was not considered in this analysis.
Economic Analysis
Economic Review: Cost–Effectiveness of SET Versus DET
Conclusions of published studies on cost-effectiveness of SET versus DET were not consistent. While some studies found that SET strategy is more cost-effective due to avoidance of multiple pregnancies, other studies either did not find any significant differences in cost per birth between SET and DET, or favoured DET as a more cost-effective option.
Ontario-Based Economic Analysis
An Ontario-based economic analysis compared cost per birth using three treatment strategies: IUI, IVF-SET, and IVF-DET. A decision-tree model assumed three cycles for each treatment option. Two separate models were considered; the first included only fresh cycles of IVF, while the second had a combination of fresh and frozen cycles. Even after accounting for cost-savings due to avoidance of multiple pregnancies (only short-term complications), IVF-SET was still associated with a highest cost per birth. The approximate budget impact to cover the first three indications for IVF listed above (severe male factor infertility, women with medical contraindications to multiple pregnancy, and couples who wish to avoid the risk of multiple pregnancy) is estimated at $9.8 to $12.8 million (Cdn). Coverage of only first two indications, namely, ICSI in patients with severe male factor infertility and infertile women with serious medical contraindications to multiple pregnancy, is estimated at $3.8 to $5.5 million Cdn.
Other Considerations
International data shows that both IVF utilization and the average number of embryos transferred in IVF cycles are influenced by IVF funding policy. The success of the SET strategy in European countries is largely due to the fact that IVF treatment is subsidized by governments.
Surveys of patients with infertility demonstrated that a significant proportion (~40%) of patients not only do not mind having multiple babies, but consider twins being an ideal outcome of infertility treatment.
A women’s age may impose some restrictions on the implementation of a SET strategy.
Conclusions and Recommendations
A review of published studies has demonstrated that IVF-SET is an effective treatment for infertility that avoids multiple pregnancies.
However, results of an Ontario-based economic analysis shows that cost savings associated with a reduction in multiple pregnancies after IVF-SET does not justify the cost of universal IVF-SET coverage by the province. Moreover, the province currently funds IUI, which has been shown to be as effective as IVF for certain types of infertility and is significantly less expensive.
In patients with severe male factor infertility, IVF in conjunction with ICSI may be the only effective treatment.
Thus, 2 indications where additional IVF access should be considered include:
IVF/ICSI for patients with severe male factor infertility
IVF-SET in infertile women with serious medical contraindications to multiple pregnancy
PMCID: PMC3379537  PMID: 23074488
7.  Large offspring syndrome 
Epigenetics  2013;8(6):591-601.
Beckwith-Wiedemann syndrome (BWS) is a human loss-of-imprinting syndrome primarily characterized by macrosomia, macroglossia, and abdominal wall defects. BWS has been associated with misregulation of two clusters of imprinted genes. Children conceived with the use of assisted reproductive technologies (ART) appear to have an increased incidence of BWS. As in humans, ART can also induce a similar overgrowth syndrome in ruminants which is referred to as large offspring syndrome (LOS). The main goal of our study is to determine if LOS shows similar loss-of-imprinting at loci known to be misregulated in BWS. To test this, Bos taurus indicus × Bos taurus taurus F1 hybrids were generated by artificial insemination (AI; control) or by ART. Seven of the 27 conceptuses in the ART group were in the > 97th percentile body weight when compared with controls. Further, other characteristics reported in BWS were observed in the ART group, such as large tongue, umbilical hernia, and ear malformations. KCNQ1OT1 (the most-often misregulated imprinted gene in BWS) was biallelically-expressed in various organs in two out of seven overgrown conceptuses from the ART group, but shows monoallelic expression in all tissues of the AI conceptuses. Furthermore, biallelic expression of KCNQ1OT1 is associated with loss of methylation at the KvDMR1 on the maternal allele and with downregulation of the maternally-expressed gene CDKN1C. In conclusion, our results show phenotypic and epigenetic similarities between LOS and BWS, and we propose the use of LOS as an animal model to investigate the etiology of BWS.
doi:10.4161/epi.24655
PMCID: PMC3857339  PMID: 23751783
BWS; LOS; KvDMR1; KCNQ1OT1; epigenetics; genomic imprinting
8.  The epigenetic imprinting defect of patients with Beckwith—Wiedemann syndrome born after assisted reproductive technology is not restricted to the 11p15 region 
Journal of Medical Genetics  2006;43(12):902-907.
Background
Genomic imprinting refers to an epigenetic marking resulting in monoallelic gene expression and has a critical role in fetal development. Various imprinting diseases have recently been reported in humans and animals born after the use of assisted reproductive technology (ART). All the epimutations implicated involve a loss of methylation of the maternal allele (demethylation of KvDMR1/KCNQ1OT1 in Beckwith–Wiedemann syndrome (BWS), demethylation of SNRPN in Angelman syndrome and demethylation of DMR2/IGF2R in large offspring syndrome), suggesting that ART impairs the acquisition or maintenance of methylation marks on maternal imprinted genes. However, it is unknown whether this epigenetic imprinting error is random or restricted to a specific imprinted domain.
Aim
To analyse the methylation status of various imprinted genes (IGF2R gene at 6q26, PEG1/MEST at 7q32, KCNQ1OT1 and H19 at 11p15.5, and SNRPN at 15q11–13) in 40 patients with BWS showing a loss of methylation at KCNQ1OT1 (11 patients with BWS born after the use of ART and 29 patients with BWS conceived naturally).
Results
3 of the 11 (27%) patients conceived using ART and 7 of the 29 (24%) patients conceived normally displayed an abnormal methylation at a locus other than KCNQ1OT1.
Conclusions
Some patients with BWS show abnormal methylation at loci other than the 11p15 region, and the involvement of other loci is not restricted to patients with BWS born after ART was used. Moreover, the mosaic distribution of epimutations suggests that imprinting is lost after fertilisation owing to a failure to maintain methylation marks during pre‐implantation development.
doi:10.1136/jmg.2006.042135
PMCID: PMC2563199  PMID: 16825435
9.  Normal epigenetic inheritance in mice conceived by in vitro fertilization and embryo transfer*  
An association between assisted reproductive technology (ART) and neurobehavioral imprinting disorders has been reported in many studies, and it seems that ART may interfere with imprint reprogramming. However, it has never been explored whether epigenetic errors or imprinting disease susceptibility induced by ART can be inherited transgenerationally. Hence, the aim of this study was to determine the effect of in vitro fertilization and embryo transfer (IVF-ET) on transgenerational inheritance in an inbred mouse model. Mice derived from IVF-ET were outcrossed to wild-type C57BL/6J to obtain their female and male line F2 and F3 generations. Their behavior, morphology, histology, and DNA methylation status at several important differentially methylated regions (DMRs) were analyzed by Morris water maze, hematoxylin and eosin (H&E) staining, and bisulfite genomic sequencing. No significant differences in spatial learning or phenotypic abnormality were found in adults derived from IVF (F1) and female and male line F2 and F3 generations. A borderline trend of hypomethylation was found in H19 DMR CpG island 3 in the female line-derived F3 generation (0.40±0.118, P=0.086). Methylation status in H19/Igf2 DMR island 1, Igf2 DMR, KvDMR, and Snrpn DMR displayed normal patterns. Methylation percentage did not differ significantly from that of adults conceived naturally, and the expression of the genes they regulated was not disturbed. Transgenerational integrity, such as behavior, morphology, histology, and DNA methylation status, was maintained in these generations, which indicates that exposure of female germ cells to hormonal stimulation and gamete manipulation might not affect the individuals and their descendents.
doi:10.1631/jzus.B1000411
PMCID: PMC3190094  PMID: 21960342
Differentially methylated regions (DMRs); In vitro fertilization and embryo transfer (IVF-ET); Central nervous system (CNS); Neurobehavioral imprinting disorders; Transgenerational epigenetic inheritance
10.  Imprinting disorders and assisted reproductive technology 
Fertility and sterility  2009;91(2):305-315.
Objective
To review currently available literature on the association between imprinting disorders (Beckwith-Wiedemann syndrome [BWS], Angleman syndrome [AS] and retinoblastoma) and assisted reproductive technologies (ART) in humans.
Design
Publications related to imprinting/epigenetic disorders including BWS, AS and retinoblastoma with ART and articles publishing outcome of ART, including IVF and ICSI, from July 1978 to February 2008 were identified using PubMed, Medline and EMBASE.
Result(s)
Considerable evidence in animal studies has demonstrated alteration in gene imprinting of embryos cultured in vitro. Publications from Europe, America and Australia have suggested an association between ART and BWS. Importantly, more than 90% of BWS in children born after ART had imprinting defects, compared to 40–50% of BWS in children conceived without ART. Moreover, there have been other reports suggesting an association between AS and ART. The majority of children with AS born after ART had an imprinting defect as the underlying etiology, specifically loss of methylation of the maternal allele. There was a single report suggesting an increased incidence of retinoblastoma in children conceived with ART.
Conclusion(s)
Because the absolute incidence of imprinting disorders is very small (< 1:12,000 births), routine screening for imprinting disorders in children conceived with ART is not recommended. Additional large cohort studies of children born after ART are needed to determine whether there is a genuine association between ART and imprinting disorders.
doi:10.1016/j.fertnstert.2009.01.002
PMCID: PMC3081604  PMID: 19201275
Imprinting disorders; epigenetic; Beckwith-Wiedemann syndrome; Angleman syndrome; retinoblastoma; assisted reproductive technology; IVF; ICSI
11.  Assessing the health and development of ART-conceived young adults: A study of feasibility, parent recall, and acceptability 
Background
Assisted reproductive technologies (ART) to treat infertility have been available for nearly three decades. There have been a number of systematic comparisons of the health and development of ART-conceived with spontaneously-conceived (SC) children. Data are equivocal, some finding no differences and others that there are more health and developmental problems in the ART group. It is agreed that perinatal mortality and morbidity are worse after assisted than spontaneous conception and the impact of the hormonally altered intrauterine environment on puberty and later fertility of offspring are unknown. To date however, there has been no investigation of the health and development of ART-conceived young adults, including from the world's few prospective cohorts of ART conceived children. Obtaining these data requires contact to be made with people at least twenty years after discharge from the treating service. Given the ethical difficulties of approaching families to participate in research up to two decades after cessation of treatment, the aim of this exploratory qualitative investigation was to assess the feasibility and acceptability of approaching mothers treated for infertility prior to 1988, and their recall of the health and development of their ART-conceived young adult children.
Methods
Mothers treated for infertility at the Royal Women's Hospital Reproductive Biology Unit in Melbourne, Australia prior to 1988 were approached by a senior clinician and invited to participate in individual semi-structured interviews which could include their partners and/or young adult children if they wished. Recruitment continued until theoretic saturation had been reached.
Results
Ten mothers, two of their husbands and five young adults participated in interviews, and the health and development of 15 ART-conceived young adults were described. The experience of conception, pregnancy, birth and the health and development of the children were recalled vividly and in detail. Families were pleased to have been approached and supported the need for systematic data collection. Mode of conception had been disclosed from childhood to all the offspring.
Conclusion
With careful and sensitive recruitment strategies it is feasible and acceptable to contact women treated for infertility at least two decades ago and their families, to assess the health and development of ART-conceived young adults.
doi:10.1186/1742-4755-5-7
PMCID: PMC2583986  PMID: 18957131
12.  Perinatal outcomes among children born by assisted reproductive techniques—a hospital-based case control study 
Background
Widespread use of assisted reproductive techniques (ART) has raised major concern about the outcome of resulting pregnancies, as well as about the health of the newborn children. The ART conceived pregnancies have an increased risk for prematurity and low birth weight (LBW). The risk of congenital malformations among children conceived via ART is contemplated to be high. The present case control study was conducted with an aim of analysing perinatal outcomes of children born by ART in the Indian context.
Methods
The case control study was conducted in the Army Hospital (Research and Referral), New Delhi. It included 82 cases and 164 controls. The data was collected on maternal and newborn characteristics among cases and controls. Perinatal outcomes were compared between ART conceived and spontaneously pregnant women in terms of birth weight, preterm, multiple pregnancies, and neonatal complications.
Results
Significant difference was observed in terms of the preterm delivery, birth weight, neonatal complications between the cases and the controls. The adjusted odds ratio (OR) was 21.6 (95% confidence interval [CI] 4.3, 112.9) for preterm delivery; 6.0 (95% CI 1.1, 43.8) for multiple pregnancy and 3.2 (95% CI 1.5, 7.0) for caesarean section. The risk of LBW and neonatal complications was heavily confounded by preterm delivery and multiple pregnancies, the adjusted OR being 0.9 and 1.0, respectively.
Conclusion
Increased risk of preterm delivery, multiple pregnancies and caesarean section was associated with ART. The LBW was confounded by preterm delivery and multiple pregnancies.
doi:10.1016/S0377-1237(12)60019-7
PMCID: PMC3862868  PMID: 24669052
assisted reproductive techniques; odds ratio; perinatal outcomes
13.  When to Start Antiretroviral Therapy in Children Aged 2–5 Years: A Collaborative Causal Modelling Analysis of Cohort Studies from Southern Africa 
PLoS Medicine  2013;10(11):e1001555.
Michael Schomaker and colleagues estimate the mortality associated with starting ART at different CD4 thresholds among children aged 2–5 years using observational data collected in cohort studies in Southern Africa.
Please see later in the article for the Editors' Summary
Background
There is limited evidence on the optimal timing of antiretroviral therapy (ART) initiation in children 2–5 y of age. We conducted a causal modelling analysis using the International Epidemiologic Databases to Evaluate AIDS–Southern Africa (IeDEA-SA) collaborative dataset to determine the difference in mortality when starting ART in children aged 2–5 y immediately (irrespective of CD4 criteria), as recommended in the World Health Organization (WHO) 2013 guidelines, compared to deferring to lower CD4 thresholds, for example, the WHO 2010 recommended threshold of CD4 count <750 cells/mm3 or CD4 percentage (CD4%) <25%.
Methods and Findings
ART-naïve children enrolling in HIV care at IeDEA-SA sites who were between 24 and 59 mo of age at first visit and with ≥1 visit prior to ART initiation and ≥1 follow-up visit were included. We estimated mortality for ART initiation at different CD4 thresholds for up to 3 y using g-computation, adjusting for measured time-dependent confounding of CD4 percent, CD4 count, and weight-for-age z-score. Confidence intervals were constructed using bootstrapping.
The median (first; third quartile) age at first visit of 2,934 children (51% male) included in the analysis was 3.3 y (2.6; 4.1), with a median (first; third quartile) CD4 count of 592 cells/mm3 (356; 895) and median (first; third quartile) CD4% of 16% (10%; 23%). The estimated cumulative mortality after 3 y for ART initiation at different CD4 thresholds ranged from 3.4% (95% CI: 2.1–6.5) (no ART) to 2.1% (95% CI: 1.3%–3.5%) (ART irrespective of CD4 value). Estimated mortality was overall higher when initiating ART at lower CD4 values or not at all. There was no mortality difference between starting ART immediately, irrespective of CD4 value, and ART initiation at the WHO 2010 recommended threshold of CD4 count <750 cells/mm3 or CD4% <25%, with mortality estimates of 2.1% (95% CI: 1.3%–3.5%) and 2.2% (95% CI: 1.4%–3.5%) after 3 y, respectively. The analysis was limited by loss to follow-up and the unavailability of WHO staging data.
Conclusions
The results indicate no mortality difference for up to 3 y between ART initiation irrespective of CD4 value and ART initiation at a threshold of CD4 count <750 cells/mm3 or CD4% <25%, but there are overall higher point estimates for mortality when ART is initiated at lower CD4 values.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Infection with HIV, the virus that causes AIDS, contributes substantially to the burden of disease in children. Worldwide, more than 3 million children younger than 15 years old (90% of whom live in sub-Saharan Africa) are HIV-positive, and every year around 330,000 more children are infected with HIV. Children usually acquire HIV from their mother during pregnancy, birth, or breastfeeding. The virus gradually destroys CD4 lymphocytes and other immune system cells, leaving infected children susceptible to other potentially life-threatening infections. HIV infection can be kept in check, with antiretroviral therapy (ART)—cocktails of drugs that have to be taken daily throughout life. ART is very effective in children but is expensive, and despite concerted international efforts over the past decade to provide universal access to ART, in 2011, less than a third of children who needed ART were receiving it.
Why Was This Study Done?
For children diagnosed as HIV-positive between the ages of two and five years, the 2010 World Health Organization (WHO) guidelines for the treatment of HIV infection recommended that ART be initiated when the CD4 count dropped below 750 cells/mm3 blood or when CD4 cells represented less than 25% of the total lymphocyte population (CD4 percent). Since June 2013, however, WHO has recommended that all HIV-positive children in this age group begin ART immediately, irrespective of their CD4 values. Earlier ART initiation might reduce mortality (death) and morbidity (illness), but it could also increase the risk of toxicity and of earlier development of drug resistance. In this causal modeling analysis, the researchers estimate the mortality associated with starting ART at different CD4 thresholds among children aged 2–5 years using observational data collected in cohort studies of ART undertaken in southern Africa. Specifically, they compared the estimated mortality associated with the WHO 2010 and WHO 2013 guidelines. Observational studies compare the outcomes of groups (cohorts) with different interventions (here, the timing of ART initiation). Data from such studies are affected by time-dependent confounding: CD4 count, for example, varies with time and is a predictor of both ART initiation and the probability of death. Causal modeling techniques take time-dependent confounding into account and enable the estimation of the causal effect of an intervention on an outcome from observational data.
What Did the Researchers Do and Find?
The researchers used g-computation (a type of causal modeling) adjusting for time-dependent confounding of CD4 percent, CD4 count, and weight-for-age z-score (a measure of whether a child is underweight for their age that provides a proxy indicator of the clinical stage of HIV infection) to estimate mortality for ART initiation at different CD4 thresholds in 2,934 ART-naïve, HIV-positive children aged 2–5 years old at their first visit to one of eight study sites in southern Africa. The average initial CD4 values of these children were a CD4 count of 592 cells/mm3 and a CD4 percent of 16%. The estimated cumulative mortality after three years was 3.4% in all children if ART was never started. If all children had started ART immediately after diagnosis irrespective of CD4 value or if the 2010 WHO-recommended threshold of a CD4 count below 750 cells/mm3 or a CD4 percent below 25% was followed, the estimated cumulative mortalities after three years were 2.1% and 2.2%, respectively (a statistically non-significant difference).
What Do These Findings Mean?
These findings suggest that, among southern African children aged 2–5 years at HIV diagnosis, there is no difference in mortality for up to three years between children in whom ART is initiated immediately and those in whom ART initiation is deferred until their CD4 value falls below a CD4 count of 750 cells/mm3 or a CD4 percent of 25%. Although causal modeling was used in this analysis, the accuracy of these results may be affected by residual confounding. For example, the researchers were unable to adjust for the clinical stage of HIV disease at HIV diagnosis and instead had to use weight-for-age z-scores as a proxy indicator of disease severity. Other limitations of the study include the large number of children lost to follow-up and a possible lack of generalizability—most of the study participants were from urban settings in South Africa. Importantly, however, these findings suggest that the recent change in the WHO guidelines for ART initiation in young children is unlikely to increase or reduce mortality, with the proviso that the long-term effects of earlier ART initiation such as toxicity and the development of resistance to ART need to be explored further.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001555
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS
NAM/aidsmap provides basic information about HIV/AIDS and summaries of recent research findings on HIV care and treatment
Information is available from Avert, an international AIDS charity, on many aspects of HIV/AIDS, including information on HIV and AIDS in Africa and on children and HIV/AIDS (in English and Spanish)
The UNAIDS World AIDS Day Report 2012 provides up-to-date information about the AIDS epidemic and efforts to halt it; the 2013 Progress Report on the Global Plan provides information on progress towards eliminating new HIV infections among children by 2015
The World Health Organization provides information about universal access to AIDS treatment (in several languages); its 2010 guidelines for ART in infants and children and its 2013 consolidated guidelines on the use of ART can be downloaded
The researchers involved in this study are part of the International Epidemiologic Databases to Evaluate AIDSSouthern Africa collaboration, which develops and implements methodology to generate the large datasets needed to address high-priority research questions related to HIV/AIDS
Personal stories about living with HIV/AIDS, including stories from young people infected with HIV, are available through Avert, through NAM/aidsmap, and through the charity website Healthtalkonline
doi:10.1371/journal.pmed.1001555
PMCID: PMC3833834  PMID: 24260029
14.  Imprinting disorders and assisted reproductive technology 
Purpose of review
To summarize current evidence in the association of imprinting disorders and assisted reproductive technology.
Recent findings
The worldwide usage of assisted reproductive technology (ART) has continued to increase since the first successful birth of a human after IVF. Since 2002, several reports have raised concerns that children conceived by ART are at increased risk of having imprinting disorders. The majority of published studies have examined DNA methylation in children conceived by ART, but results are conflicting. Beckwith–Wiedemann syndrome and Angelman syndrome are the most extensively studied imprinting disorders and multiple case series and reports have been published on ART-conceived children with these syndromes. Overall the majority of reports suggest that ART might be associated with Beckwith–Wiedermann syndrome and Angelman syndrome, but larger collaborative studies need to be performed.
Summary
The current data suggest an association between imprinting disorders and ART although the absolute risk appears to be low. However, animal studies have established biologic plausibility and there is continuing concern about the possibility of epigenetic changes resulting from ART.
doi:10.1097/MED.0b013e32834040a3
PMCID: PMC3124339  PMID: 20962636
Angelman syndrome; assisted reproductive technology; Beckwith–Wiedemann syndrome; DNA methylation; imprinting disorders
15.  Imprinting Disorders and Assisted Reproductive Technology 
Seminars in reproductive medicine  2009;27(5):417-428.
Worldwide use of assisted reproductive technology (ART) accounts for an estimated 1 to 3% of births. Since 2002, a series of reports have suggested an increased risk of imprinting disorders (Beckwith-Wiedemann syndrome and Angelman syndrome) in children conceived by ART. Definitive conclusions are difficult to substantiate due to the rarity of imprinting disorders and the variability in ART protocols. Despite these limitations, there is biological plausibility for alteration in nongenomic inheritance caused by ART. Animal studies have shown that ART procedures can alter normal imprinting, specifically DNA methylation patterns. Collectively, studies suggest an association between ART and loss of maternal methylation. More recent reports examined a possible association between ART and global hypomethylation of DNA. Three other imprinting disorders (Silver-Russell syndrome, maternal hypomethylation syndrome, and retinoblastoma) have also been implicated, but there is insufficient evidence to establish an association of these syndromes with ART. Based on current evidence, the absolute risk of imprinting disorders after ART remains small and does not warrant routine screening. Large prospective studies are needed to better understand the risks associated with imprinting disorders, imprinting defects, and ART.
doi:10.1055/s-0029-1237430
PMCID: PMC2755197  PMID: 19711252
Assisted reproductive technology; ART; imprinting disorders; nongenomic inheritance; loss of maternal methylation; DNA methylation; BWS; AS
16.  DNA methylation and gene expression differences in children conceived in vitro or in vivo 
Human Molecular Genetics  2009;18(20):3769-3778.
Epidemiological data indicate that children conceived in vitro have a greater relative risk of low birth-weight, major and minor birth defects, and rare disorders involving imprinted genes, suggesting that epigenetic changes may be associated with assisted reproduction. We examined DNA methylation at more than 700 genes (1536 CpG sites) in placenta and cord blood and measured gene expression levels of a subset of genes that differed in methylation levels between children conceived in vitro versus in vivo. Our results suggest that in vitro conception is associated with lower mean methylation at CpG sites in placenta and higher mean methylation at CpG sites in cord blood. We also find that in vitro conception-associated DNA methylation differences are associated with gene expression differences at both imprinted and non-imprinted genes. The range of inter-individual variation in gene expression of the in vitro and in vivo groups overlaps substantially but some individuals from the in vitro group differ from the in vivo group mean by more than two standard deviations. Several of the genes whose expression differs between the two groups have been implicated in chronic metabolic disorders, such as obesity and type II diabetes. These findings suggest that there may be epigenetic differences in the gametes or early embryos derived from couples undergoing treatment for infertility. Alternatively, assisted reproduction technology may have an effect on global patterns of DNA methylation and gene expression. In either case, these differences or changes may affect long-term patterns of gene expression.
doi:10.1093/hmg/ddp319
PMCID: PMC2748887  PMID: 19605411
17.  Role of ART in Imprinting Disorders 
Seminars in reproductive medicine  2012;30(2):10.1055/s-0032-1307417.
Assisted reproductive technologies (ART) offer revolutionary infertility treatments for millions of childless couples around the world. Currently, ART accounts for 1 to 3% of annual births in industrialized countries and continues to expand rapidly. Except for an increased incidence of premature births, these technologies are considered safe. However, new evidence published during the past decade has suggested an increased incidence of imprinting disorders in children conceived by ART. Specifically, an increased risk was reported for Beckwith-Wiedemann syndrome (BWS), Angelman syndrome (AS), Silver-Russell syndrome, and retinoblastoma. In contrast, some studies have found no association between ART and BWS, AS, Prader-Willi syndrome, transient neonatal diabetes mellitus, and retinoblastoma. The variability in ART protocols and the rarity of imprinting disorders complicate determining the causative relationship between ART and an increased incidence of imprinting disorders. Nevertheless, compelling experimental data from animal studies also suggest a link between increased imprinting disorders and ART. Further comprehensive, appropriately powered studies are needed to better address the magnitude of the risk for ART-associated imprinting disorders. Large longitudinal studies are particularly critical to evaluate long-term effects of ART not only during the perinatal period but also into adulthood. An important consideration is to determine if the implicated association between ART and imprinting disorders is actually related to the procedures or to infertility itself.
doi:10.1055/s-0032-1307417
PMCID: PMC3838883  PMID: 22549709
Epigenetics; genomic Imprinting; methylation; imprinting disorders; ART
18.  Are there subtle, genome-wide epigenetic alterations in normal offspring conceived from Assisted Reproductive Technologies? 
Fertility and sterility  2011;96(6):1306-1311.
Objective
To review recent data regarding subtle, but widespread epigenetic alterations in phenotypically normal offspring conceived of ART compared to offspring conceived in vivo.
Design
A PubMed computer search was performed to identify relevant articles.
Setting
Research institution.
Intervention(s)
None.
Result(s)
Studies in animals indicate that in vitro culture may be associated with widespread alterations in imprinted genes, compared to in vivo-conceived offspring. Recently, studies in humans have likewise demonstrated widespread changes in DNA methylation, including genes linked to adipocyte development, insulin signaling, and obesity in offspring conceived by ART, compared to in vivo-conceived children. Changes in multiple imprinted genes following ART were also noted in additional studies, which suggested that the diagnosis of infertility may explain the differences between in vivo-conceived and ART offspring.
Conclusion(s)
These data suggest that ART is associated with widespread epigenetic modifications in phenotypically normal children, and that these modifications may increase risk of adverse cardiometabolic outcomes. Further research is needed to elucidate the possible relationship between ART, genome-wide alterations in imprinted genes, and their potential relevance to subtle cardiometabolic consequences reported in ART offspring.
doi:10.1016/j.fertnstert.2011.09.037
PMCID: PMC3576017  PMID: 22035969
genome-wide epigenetic; imprinting; epigenetics; assisted reproductive technology; cardiometabolic
19.  Effects of Assisted Reproduction Technology on Placental Imprinted Gene Expression 
We used placental tissue to compare the imprinted gene expression of IGF2, H19, KCNQ1OT1, and CDKN1C of singletons conceived via assisted reproduction technology (ART) with that of spontaneously conceived (SC) singletons. Of 989 singletons examined (ART n = 65; SC n = 924), neonatal weight was significantly lower (P < .001) in the ART group than in the SC group, but placental weight showed no significant difference. Gene expression analyzed by real-time PCR was similar for both groups with appropriate-for-date (AFD) birth weight. H19 expression was suppressed in fetal growth retardation (FGR) cases in the ART and SC groups compared with AFD cases (P < .02 and P < .05, resp.). In contrast, CDKN1C expression was suppressed in FGR cases in the ART group (P < .01), while KCNQ1OT1 expression was hyperexpressed in FGR cases in the SC group (P < .05). As imprinted gene expression patterns differed between the ART and SC groups, we speculate that ART modifies epigenetic status even though the possibilities always exist.
doi:10.1155/2010/437528
PMCID: PMC2913850  PMID: 20706653
20.  Imprinting methylation errors in ART 
Reproductive Medicine and Biology  2014;13(4):193-202.
There has been an increase in incidence reports of rare imprinting disorders associated with assisted reproductive technology (ART). ART, including in vitro fertilization and intracytoplasmic sperm injections, is an important treatment for infertile people of reproductive age and increasingly produces children. The identification of epigenetic changes at imprinted loci in ART infants has led to the suggestion that ART techniques themselves may predispose embryos to acquire imprinting errors and diseases. In this review, we note that the particular steps of ART may be prone to induction of imprinting methylation errors during gametogenesis, fertilization and early embryonic development. In addition, we explain imprint-associated diseases and their causes. Moreover, from a Japanese nationwide epidemiological study of imprint-associated diseases, we determine their associations with ART. Epigenetic studies will be required to understand the pathogenesis, ART-related risk factor(s) and what precautions can be taken to prevent the occurrence of input methylation errors. We hope that the constitution of children born after each ART procedure will reveal the safest and most ethical approach to use, which will be invaluable for the future development of standard ART.
doi:10.1007/s12522-014-0183-3
PMCID: PMC4182590  PMID: 25298744
Assisted reproductive technologies (ART); DNA methylation; Genomic imprinting; Intracytoplasmic sperm injection (ICSI); In vitro fertilization (IVF)
21.  An overview of studies on psychological well-being in children born following assisted reproductive technologies*  
Over the course of the past 35 years, assisted reproductive technologies (ARTs) have been increasingly used worldwide, while debates on their safety have been generated. Birth defects and imprinting disorders were reported in previous research. Thus, the psychological development of children born following ARTs has become a major concern nowadays. This review gives a systematic view of psychological well-being of children conceived by different types of ART, including in vitro fertilization, intracytoplasmic sperm injection (ICSI), preimplantation genetic diagnosis/screening, and in vitro maturation. The previous studies are analyzed in three sections: (1) cognitive, motor, and language developments, (2) behavior problems and socio-emotional development, and (3) parent-child relationship. We conclude that although the majority of the studies on cognitive, motor, and language developments reported comparable achievements in the ART group vs. the naturally conceived group, lower intelligence quotient (IQ) scores, worse visual-motor ability or locomotor development, and delayed receptive language competence were found in the ART group. The results on the socio-emotional development were reassuring. As for the behavior problems, a higher prevalence of behavior problems existed in ART children; moreover, ICSI children were found to be at a higher risk of autism than the general population. Meanwhile, ART parents tended to have positive parental attitudes and be more protective of their children. Some suggestions for further research are also given in this review.
doi:10.1631/jzus.B1300101
PMCID: PMC3829644  PMID: 24190441
Assisted reproductive technologies; Psychological well-being; Behavior problems; Parent-child relationship
22.  Specific epigenetic alterations of IGF2-H19 locus in spermatozoa from infertile men 
DNA methylation marks, a key modification of imprinting, are erased in primordial germ cells and sex specifically re-established during gametogenesis. Abnormal epigenetic programming has been proposed as a possible mechanism compromising male fertility. We analysed by pyrosequencing the DNA methylation status of 47 CpGs located in differentially methylated regions (DMRs), the DMR0 and DMR2 of the IGF2 gene and in the 3rd and 6th CTCF-binding sites of the H19 DMR in human sperm from men with normal semen and patients with teratozoospermia (T) and/or oligo-astheno-teratozoospermia (OAT). All normal semen samples presented the expected high global methylation level for all CpGs analysed. In the teratozoospermia group, 11 of 19 patients presented a loss of methylation at variable CpG positions either in the IGF2 DMR2 or in both the IGF2 DMR2 and the 6th CTCF of the H19 DMR. In the OAT group, 16 of 22 patients presented a severe loss of methylation of the 6th CTCF, closely correlated with sperm concentration. The methylation state of DMR0 and of the 3rd CTCF was never affected by the pathological status of sperm samples. This study demonstrates that epigenetic perturbations of the 6th CTCF site of the H19 DMR might be a relevant biomarker for quantitative defects of spermatogenesis in humans. Moreover, we defined a methylation threshold sustaining the classification of patients in two groups, unmethylated and methylated. Using this new classification of patients, the observed intrinsic imprinting defects of spermatozoa appear not to impair significantly the outcome of assisted reproductive technologies.
doi:10.1038/ejhg.2009.117
PMCID: PMC2987171  PMID: 19584898
genomic imprinting; IGF2-H19 locus; methylation; pyrosequencing; spermatozoa; assisted reproductive technologies (ART)
23.  Health and Development of Children Born after Assisted Reproductive Technology and Sub-Fertility Compared to Naturally Conceived Children: Data from a National Study 
Pediatric Reports  2014;6(1):5118.
In a non-matched case-control study using data from two large national cohort studies, we investigated whether indicators of child health and development up to 7 years of age differ between children conceived using assisted reproductive technology (ART), children born after sub-fertility (more than 24 months of trying for conception) and other children. Information on ART use/sub-fertility was available for 23,649 children. There were 227 cases (children conceived through ART) and two control groups: 783 children born to sub-fertile couples, and 22,639 children born to couples with no fertility issues. In models adjusted for social and demographic factors there were significant differences between groups in rate of hospital admissions before the children were 9 months old (P=0.029), with the ART group showing higher rates of hospital admission than the no fertility issues control group, the sub-fertile control group being intermediate between the two. Children born after ART had comparable health and development beyond 9 months of age to their naturally conceived peers. This applied to the whole sample and to a sub-sample of children from deprived neighborhoods.
doi:10.4081/pr.2014.5118
PMCID: PMC3977159  PMID: 24711911
assisted reproductive technology; child health; sub-fertility
24.  Comparison of Congenital Abnormalities of Infants Conceived by Assisted Reproductive Techniques versus Infants with Natural Conception in Tehran 
Background:
In many countries, 1 to 3% of newborn infants are conceived by assisted reproductive techniques (ART). Despite the success of ART, there is concern about the risk of congenital malformations among these infants. We report our experience to determine whether use of ART is associated with an increase in major congenital malformations or adverse pregnancy outcomes.
Materials and Methods:
Historical cohort study of major congenital malformations (MCM) was performed in 978 births from January 2008 to December 2010. The data for this analysis were derived from a Tehran’s ART linked data file by simple sampling method. In our study, the risk of congenital malformations was compared in 326 ART infants and 652 naturally conceived (NC) infants. We also performed multiple logistic regression analyses to calculate the odds ratio (OR) and 95% confidence intervals (CI) for the independent association of ART on each outcome.
Results:
We found 56 infants with major congenital malformations, these included 29 NC infants (4.4%) and 27 ART infants (8.3%). In comparison with NC infants, ART infants had a significant 1.94-fold increased risk of MCM.After adjustment for maternal age, infant’s sex stillbirth, abortion and type of delivery, we found a relatively small difference in risk (OR=2.04). In this study the majority (94.3%) of all infants were normal but 5.7% of infants had at least one MCM. The prevalence rate for the intracytoplasmic sperm injection (ICSI) was 6.5% for the In vitro fertilisation (IVF) group was 15.9% or 2.73-fold higher than ICSI group (P=0.018). Also we ignore the possible role of genotype and other unknown factors in causing more malformations in ART infants.
Conclusion:
Other studies have shown a slightly increased risk of major congenital malformations in pregnancies resulting from ART. Likewise, this study reports a greater risk of MCMs in ART infants than in naturally conceived infants. We also found evidence of a difference in risk of MCMs between IVF and ICSI. Musculoskeletal and urogenital malformations were the most reported MCMs in ART infants according to organs and systems classification.
PMCID: PMC3914490  PMID: 24520489
Infants; Assisted Reproductive Technique; Congenital Malformations; Anomaly; Conception; Fertilization
25.  Infertility, infertility treatment, and congenital malformations: Danish national birth cohort 
BMJ : British Medical Journal  2006;333(7570):679.
Objectives To examine whether infertile couples (with a time to pregnancy of > 12 months), who conceive naturally or after treatment, give birth to children with an increased prevalence of congenital malformations.
Design Longitudinal study.
Setting Danish national birth cohort.
Participants Three groups of liveborn children and their mothers: 50 897 singletons and 1366 twins born of fertile couples (time to pregnancy ≤ 12 months), 5764 singletons and 100 twins born of infertile couples who conceived naturally (time to pregnancy > 12 months), and 4588 singletons and 1690 twins born after infertility treatment.
Main outcome measures Prevalence of congenital malformations determined from hospital discharge diagnoses.
Results Compared with singletons born of fertile couples, singletons born of infertile couples who conceived naturally or after treatment had a higher prevalence of congenital malformations—hazard ratios 1.20 (95% confidence interval 1.07 to 1.35) and 1.39 (1.23 to 1.57). The overall prevalence of congenital malformations increased with increasing time to pregnancy. When the analysis was restricted to singletons born of infertile couples, babies born after treatment had an increased prevalence of genital organ malformations (hazard ratio 2.32, 1.24 to 4.35) compared with babies conceived naturally. No significant differences existed in the overall prevalence of congenital malformations among twins.
Conclusions Hormonal treatment for infertility may be related to the occurrence of malformations of genital organs, but our results suggest that the reported increased prevalence of congenital malformations seen in singletons born after assisted reproductive technology is partly due to the underlying infertility or its determinants. The association between untreated infertility and congenital malformations warrants further examination.
doi:10.1136/bmj.38919.495718.AE
PMCID: PMC1584372  PMID: 16893903

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