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1.  Vasoactive Exposures during Pregnancy and Risk of Microtia 
Little is known about the etiology of nonsyndromic microtia. This study investigated the hypothesis that microtia is caused by vascular disruption.
The study analyzed data from the population-based National Birth Defects Prevention Study (NBDPS) for deliveries between 1997 and 2005. Four hundred eleven nonsyndromic cases of microtia, with or without additional defects, were compared to 6560 nonmalformed infants with respect to maternal exposures to vasoactive medications and smoking during the periconceptional period and conditions that have previously been associated with vascular events (multiple gestation, maternal history of type 1, type 2, or gestational diabetes, and hypertension). Odds ratios (ORs) were estimated with multivariable models, controlling for the effects of race/ethnicity, education, periconceptional folic acid use, and study center.
Risk estimates for vasoactive medications and smoking were not meaningfully increased. Maternal type 1/2 diabetes was diagnosed before or during the index pregnancy in 4% and 1% of cases, respectively, compared to 1% and 0.05% of controls; the adjusted OR for these two groups combined was 7.2 (95% confidence interval [CI], 3.9–13.1). Gestational diabetes was observed for 9% of cases and 6% of controls; the OR was moderately elevated (OR, 1.4; 95% CI, 0.9–2.0). ORs were also increased for multiple gestations (OR, 2.5; 95% CI, 1.5–4.2) and pre-existing hypertension (OR, 1.6; 95% CI, 1.0–2.5).
Because ORs were only elevated for diabetes and not for vasoactive exposures or other potential vascular events, findings suggest that some microtia occurrences may be part of the diabetic embryopathy rather than manifestations of vascular disruption.
PMCID: PMC4521508  PMID: 23180593
birth defect; microtia; anotia; ear; epidemiology; diabetes mellitus; pregnancy; medication
3.  Estimate of the potential impact of folic acid fortification of corn masa flour on the prevention of neural tube defects 
Hispanics in the US have a higher prevalence of neural tube defect (NTD)-affected pregnancies than non-Hispanic whites, and lower median total folic acid (FA) intake. FA fortification of corn masa flour (CMF) is a policy-level intervention for NTD prevention; however, the impact on NTD prevalence has not been estimated.
We developed a model to estimate the percentage reduction in prevalence of spina bifida and anencephaly that could occur with FA fortification of CMF. Model inputs included estimates of the percentage reduction in prevalence attributed to FA fortification of enriched cereal grain products (ECGP) (1995–1996 vs. 1998–2002), the increase in median FA intake after ECGP fortification, and the estimated increase in median FA intake that could occur with CMF fortification at the same level as ECGP (140μg/100g). We used Monte Carlo simulation to quantify uncertainty. We stratified analyses by racial/ethnic group and rounded results to the nearest 10.
We estimated CMF fortification could prevent 30 Hispanic infants from having spina bifida (95% uncertainty interval: 0,80) and 10 infants from having anencephaly (95% uncertainty interval: 0,40) annually. The estimated impact among non-Hispanic whites and blacks was smaller.
CMF fortification with FA could prevent from 0 to 120 infants, with the most likely value of approximately 40, from having spina bifida or anencephaly among Hispanics, the population most likely to benefit from the proposed intervention. While this estimated reduction is unlikely to be discernible using current birth defect surveillance methods, it suggests an important benefit to the target population.
PMCID: PMC4515957  PMID: 24142499
neural tube defects; folic acid; fortification; prevention
4.  Using the Electronic Medical Record to Refer Women Taking Category D or X Medications for Teratogen and Contraceptive Counseling 
Women taking teratogens may not receive teratogen and contraceptive counseling. The objective of this study is to explore the feasibility of an electronic medical record (EMR) alert and referral system to improve teratogen and contraceptive counseling.
We conducted a descriptive study in an academic outpatient setting to evaluate the feasibility of an EMR alert and referral system. Reproductive age women taking category D or X medications seen in family medicine clinics were referred by means of an EMR alert for teratogen and contraceptive counseling. A subset of these women consented to follow-up surveys assessing contraceptive usage before counseling, intended contraceptive method after counseling and satisfaction with the counseling. Participants were contacted at 1 and 3 months to assess contraceptive usage.
A total of 354 women were prescribed category D or X medications by clinicians who received the EMR alert, 170 women were referred, 59 women received counseling, and 33 participants enrolled in the study. One participant did not use any contraception. Among the 32 participants using contraception, 12 (37.5%) used oral contraceptives, 11 (34.4%) used condoms, 3 (9.4%) used withdrawal, 3 (9.4%) used intrauterine devices, 2 (6.3%) used contraceptive rings, and 1 (3.1%) used the diaphragm. After counseling, one-third of participants were considering more effective contraception. Almost all participants strongly agreed or agreed that the counseling was helpful.
Creating an EMR alert and referral system for women prescribed category X or D medications is feasible. Counseling on teratogen exposure and contraception may improve the acceptability of more effective contraception.
PMCID: PMC4509843  PMID: 26100297
teratogen; contraception; electronic medical records; medication safety; collaboration
5.  Barriers to Care for Children with Orofacial Clefts in North Carolina 
Little is known about the barriers faced by families of children with birth defects in obtaining healthcare. We examined reported perceived barriers to care and satisfaction with care among mothers of children with orofacial clefts.
In 2006, a validated barriers to care mail/phone survey was administered in North Carolina to all resident mothers of children with orofacial clefts born between 2001 and 2004. Potential participants were identified using the North Carolina Birth Defects Monitoring Program, an active, state-wide, population-based birth defects registry. Five barriers to care subscales were examined: pragmatics, skills, marginalization, expectations, and knowledge/beliefs. Descriptive and bivariate analyses were conducted using chi-square and Fisher's exact tests. Results were stratified by cleft type and presence of other birth defects.
Of 475 eligible participants, 51.6% (n = 245) responded. The six most commonly reported perceived barriers to care were all part of the pragmatics subscale: having to take time off work (45.3%); long waits in the waiting rooms (37.6%); taking care of household responsibilities (29.7%); meeting other family members' needs (29.5%); waiting too many days for appointments (27.0%); and cost (25.0%). Most respondents (72.3%, 175/242) felt “very satisfied” with their child's cleft care.
Although most participants reported being satisfied with their child's care, many perceived barriers to care were identified. Due to the limited understanding and paucity of research on barriers to care for children with birth defects, including orofacial clefts, additional research on barriers to care and factors associated with them are needed.
PMCID: PMC4507417  PMID: 25200965
health services accessibility; access to health care; orofacial clefts; cleft lip; cleft palate; birth defects
6.  Factors Associated with Distance and Time Traveled to Cleft and Craniofacial Care 
Information on travel distance and time to care for children with birth defects is lacking. We examined factors associated with travel distance and time to cleft care among children with orofacial clefts.
In 2006, a mail/phone survey was administered in English and Spanish to all resident mothers of children with orofacial clefts born 2001 to 2004 and identified by the North Carolina birth defects registry. We analyzed one-way travel distance and time and the extent to which taking a child to care was a problem. We used multivariable logistic regression to examine the association between selected sociodemographic factors and travel distance (≤60 miles and >60 miles) and time (≤60 min and >60 min) to cleft care.
Of 475 eligible participants, 51.6% (n = 245) responded. Of the respondents, 97.1% (n = 238) were the child’s biological mother. Approximately 83% (n = 204) of respondents were non-Hispanic White; 33.3% (n = 81) were college educated; and 50.0% (n = 115) had private health insurance. One-way mean and median travel distances were 80 and 50 miles, respectively (range, 0–1058 miles). One-way mean and median travel times were 92 and 60 min, respectively (range, 5 min to 8 hr). After adjusting for selected sociodemographics, travel distance varied significantly by maternal education, child’s age, and cleft type. Travel time varied significantly by child’s age. Approximately 67% (n = 162) reported taking their child to receive care was not a problem.
Approximately 48% of respondents traveled > 1 hr to receive cleft care. Increasing access to care may be important for improving health outcomes among this population.
PMCID: PMC4507418  PMID: 24039055
barriers to care; health care accessibility; travel time; travel distance; cleft lip; cleft palate; orofacial clefts
7.  Modeling Travel Impedance to Medical Care for Children with Birth Defects Using Geographic Information Systems 
Children with birth defects may face significant geographic barriers accessing medical care and specialized services. Using a Geographic Information Systems–based approach, one-way travel time and distance to access medical care for children born with spina bifida was estimated.
Using 2007 road information from the Florida Department of Transportation, we built a topological network of Florida roads. Live-born Florida infants with spina bifida during 1998 to 2007 were identified by the Florida Birth Defects Registry and linked to hospital discharge records. Maternal residence at delivery and hospitalization locations were identified during the first year of life.
Of 668 infants with spina bifida, 8.1% (n = 54) could not be linked to inpatient data, resulting in 614 infants. Of those 614 infants, 99.7% (n = 612) of the maternal residential addresses at delivery were successfully geocoded. Infants with spina bifida living in rural areas in Florida experienced travel times almost twice as high compared with those living in urban areas. When aggregated at county levels, one-way network travel times exhibited statistically significant spatial autocorrelation, indicating that families living in some clusters of counties experienced substantially greater travel times compared with families living in other areas of Florida.
This analysis demonstrates the usefulness of linking birth defects registry and hospital discharge data to examine geographic differences in access to medical care. Geographic Information Systems methods are important in evaluating accessibility and geographic barriers to care and could be used among children with special health care needs, including children with birth defects.
PMCID: PMC4507419  PMID: 23996978
birth defects; spina bifida; medical care; geocoding; GIS; network modeling; travel distance; travel time
8.  Hospital Use, Associated Costs, and Payer Status for Infants Born with Spina Bifida 
Health care use and costs for children with spina bifida (SB) are significantly greater than those of unaffected children. Little is known about hospital use and costs across health insurance payer types. We examined hospitalizations and associated costs by sociodemographic characteristics and payer type during the first year of life among children with SB. We also examined changes in health insurance payer status.
This study was a retrospective, statewide population-based analysis of infants with SB without anencephaly born in Florida during 1998–2007. Infants were identified by the Florida Birth Defects Registry and linked to hospital discharge records. Descriptive statistics on number of hospitalizations, length of stay, and estimated hospital costs per hospitalization and per infant were calculated during the first year of life. Results were stratified by selected sociodemographic variables and health insurance payer type.
Among 615 infants with SB, mean and median numbers of hospitalizations per infant were 2.4 and 2.0, respectively. Mean and median total days of hospitalization per infant were 25.2 and 14.0 days, respectively. Approximately 18% of infants were hospitalized more than three times. Among infants with multiple hospitalizations, 16.7% had a mix of public and private health insurance payers. Almost 60% of hospitalizations for infants were paid by public payer sources. Mean and median estimated hospital costs per infant were $39,059 and $21,937, respectively.
Results suggest a small percentage of infants with SB have multiple hospitalizations with high costs. Further analysis on factors associated with length of stay, hospitalizations, and costs is warranted.
PMCID: PMC4507424  PMID: 23115108
spina bifida; healthcare use; hospital costs; health insurance; payer type
9.  Human Teratogens Update 2011: Can We Ensure Safety during Pregnancy? 
Anniversaries of the identification of three human teratogens (i.e., rubella virus in 1941, thalidomide in 1961, and diethylstilbestrol in 1971) occurred in 2011. These experiences highlight the critical role that scientists with an interest in teratology play in the identification of teratogenic exposures as the basis for developing strategies for prevention of those exposures and the adverse outcomes associated with them. However, an equally important responsibility for teratologists is to evaluate whether medications and vaccines are safe for use during pregnancy so informed decisions about disease treatment and prevention during pregnancy can be made. Several recent studies have examined the safety of medications during pregnancy, including antiviral medications used to treat herpes simplex and zoster, proton pump inhibitors used to treat gastroesophageal reflux, and newer-generation antiepileptic medications used to treat seizures and other conditions. Despite the large numbers of pregnant women included in these studies and the relatively reassuring results, the question of whether these medications are teratogens remains. In addition, certain vaccines are recommended during pregnancy to prevent infections in mothers and infants, but clinical trials to test these vaccines typically exclude pregnant women; thus, evaluation of their safety depends on observational studies. For pregnant women to receive optimal care, we need to define the data needed to determine whether a medication or vaccine is “safe” for use during pregnancy. In the absence of adequate, well-controlled data, it will often be necessary to weigh the benefits of medications or vaccines with potential risks to the embryo or fetus.
PMCID: PMC4490791  PMID: 22328359
10.  The Association Between Reported Venlafaxine Use in Early Pregnancy and Birth Defects, National Birth Defects Prevention Study, 1997–2007 
Few epidemiologic studies have investigated the use of venlafaxine (Effexor®), an antidepressant used to treat major depression and anxiety disorders in adults, during pregnancy. Our objective was to determine whether use of venlafaxine during pregnancy is associated with specific birth defects.
We used data from the National Birth Defects Prevention Study (NBDPS), a population-based, case-control study in the United States. Our analysis included mothers with pregnancies affected by one of 30 selected birth defects (cases) and babies without birth defects (controls) with estimated dates of delivery between 1997–2007. Exposure was any reported use of venlafaxine from one month preconception through the third month of pregnancy. We calculated adjusted odds ratios (aORs) and 95% Fisher’s Exact confidence intervals (CIs) for 24 birth defect groups for which at least 400 case mothers were interviewed. Our adjusted analyses controlled for maternal age and race-ethnicity.
Among the 27,045 NBDPS participants who met inclusion criteria, 0.17% (14/8,002) of control mothers and 0.40% (77/19,043) of case mothers reported any use of venlafaxine from one month preconception through the third month of pregnancy. Statistically significant associations were found for anencephaly, atrial septal defect (ASD) secundum or ASD not otherwise specified, coarctation of the aorta, cleft palate, and gastroschisis.
Our data suggest associations between periconceptional use of venlafaxine and some birth defects. However, sample sizes were small, confidence intervals were wide, and additional studies are needed to confirm these results.
PMCID: PMC4484721  PMID: 23281074
Venlafaxine; Birth Defects; Pregnancy; Antidepressants; Epidemiology
11.  Proportion of Neural Tube Defects Attributable to Known Risk Factors 
Recognized risk factors for neural tube defects (NTDs) poorly predict population-level NTD risk. However, the proportion of NTDs that can be attributed to these risk factors is uncertain.
To determine the proportion of NTD cases that is attributable to known or suspected risk factors (i.e., female infant sex, family history of NTDs, and maternal Hispanic ethnicity, obesity, pregestational diabetes, gestational diabetes, low dietary folate intake, lack of folic acid supplementation, anticonvulsant use, and hot tub or sauna use), we estimated the adjusted population attributable fraction (aAF) for each factor, using the method of Eide and Geffler and data from the National Birth Defects Prevention Study.
Our analyses of these data indicate that the proportion of cases of spina bifida and anencephaly that can be attributed to known risk factors is 28% and 44%, respectively. For spina bifida, the factor with the greatest attributable fraction was maternal obesity (aAF, 10%), whereas for anencephaly it was Hispanic ethnicity (aAF, 15%).
Our analyses indicate that known risk factors account for <50% of NTD cases. Hence, the majority of NTD cases are attributable to, as yet, unidentified factors. These findings highlight the need for continued research to identify genetic and additional nongenetic risk factors for NTDs. Further, these findings suggest that strategies that aim to reduce the risk of NTDs associated with maternal Hispanic ethnicity and obesity may have the greatest impact on the population prevalence of these conditions.
PMCID: PMC4482342  PMID: 23427344
12.  Spatial analysis of gastroschisis in the National Birth Defects Prevention Study 
Gastroschisis is a birth defect where loops of bowel are protruding from the abdominal wall at birth. Previous research has suggested that gastroschisis cases can occur in clusters. The objective of this study was to identify if there were areas of elevated gastroschisis risk using data from the National Birth Defects Prevention Study (NBDPS), 1997 through 2007.
We obtained data on cases (n=371) through population-based birth defects surveillance systems in Arkansas, California, and Utah; controls (n=2,359) were selected from the same geographic areas as cases. Mothers were interviewed on demographic information and exposures during pregnancy, including residential history. We used first trimester maternal addresses and generalized additive models to create a continuous map surface of odds ratios (OR) by smoothing over latitude and longitude. Permutation tests were used to assess whether location of maternal residence was important and identify locations with statistically significant ORs.
In Arkansas, adjusted ORs in the southwest corner were 2.0 and the global deviance was not statistically significant (p-value: 0.57). Adjusted ORs for California indicated areas of increased risk with ORs 1.3 (p-value: 0.34). In Utah, the adjusted ORs were elevated (OR: 2.4) in the south-eastern corner of the study area (p-value: 0.34).
The results of this study, while not statistically significant, suggest there were spatial variations in gastroschisis births. We cannot rule out that these variations were due to edge effects or residual confounding.
PMCID: PMC4478213  PMID: 25850424
Gastroschisis; Congenital Abnormalities; Spatial Analysis
13.  Is Maternal Parity an Independent Risk Factor for Birth Defects? 
Although associations between maternal parity and birth defects have been observed previously, few studies have focused on the possibility that parity is an independent risk factor for birth defects. We investigated the relation between levels of parity and a range of birth defects, adjusting each defect group for the same covariates.
We included infants who had an estimated delivery date between 1997 and 2007 and participated in the National Birth Defects Prevention Study, a multisite case-control study. Cases included infants or fetuses belonging to 38 phenotypes of birth defects (n = 17,908), and controls included infants who were unaffected by a major birth defect (n = 7173). Odds ratios (ORs) were adjusted for 12 covariates using logistic regression.
Compared with primiparous mothers, nulliparous mothers were more likely to have infants with amniotic band sequence, hydrocephaly, esophageal atresia, hypospadias, limb reduction deficiencies, diaphragmatic hernia, omphalocele, gastroschisis, tetralogy of Fallot, and septal cardiac defects, with significant ORs (1.2 to 2.3). Compared with primiparous mothers, multiparous mothers had a significantly increased risk of omphalocele, with an OR of 1.5, but had significantly decreased risk of hypospadias and limb reduction deficiencies, with ORs of 0.77 and 0.77.
Nulliparity was associated with an increased risk of specific phenotypes of birth defects. Most of the phenotypes associated with nulliparity in this study were consistent with those identified by previous studies. Research into biologic or environmental factors that are associated with nulliparity may be helpful in explaining some or all of these associations.
PMCID: PMC4476024  PMID: 22371332
nulliparity; multiparity; parity; congenital abnormalities; congenital heart defects
14.  An In Vitro Mouse Model of Congenital Cytomegalovirus-induced Pathogenesis of the Inner Ear Cochlea 
Congenital human cytomegalovirus (CMV) infection is the leading nongenetic etiology of sensorineural hearing loss (SNHL) at birth and prelingual SNHL not expressed at birth. The paucity of temporal bone autopsy specimens from infants with congenital CMV infection has hindered the critical correlation of histopathology with pathogenesis. Here, we present an in vitro embryonic mouse model of CMV-infected cochleas that mimics the human sites of viral infection and associated pathology. There is a striking dysplasia/hyperplasia in mouse CMV-infected cochlear epithelium and mesenchyme, including organ of Corti hair and supporting cells and stria vascularis. This is concomitant with significant dysregulation of p19, p21, p27, and Pcna gene expression, as well as proliferating cell nuclear antigen (PCNA) protein expression. Other pathologies similar to those arising from known deafness gene mutations include downregulation of KCNQ1 protein expression in the stria vascularis, as well as hypoplastic and dysmorphic melanocytes. Thus, this model provides a relevant and reliable platform within which the detailed cell and molecular biology of CMV-induced deafness may be studied.
PMCID: PMC4476032  PMID: 23281115
congenital cytomegalovirus infection; sensorineural hearing loss; in vitro mouse model; cochlear pathogenesis
15.  Hospitalizations, Costs, and Mortality among Infants with Critical Congenital Heart Disease: How Important Is Timely Detection? 
Critical congenital heart disease (CCHD) was recently added to the U.S. Recommended Uniform Screening Panel for newborns. States considering screening requirements may want more information about the potential impact of screening. This study examined potentially avoidable mortality among infants with late detected CCHD and assessed whether late detection was associated with increased hospital resource use during infancy.
This was a state-wide, population-based, observational study of infants with CCHD (n =3603) born 1998 to 2007 identified by the Florida Birth Defects Registry. We examined 12 CCHD conditions that are targets of newborn screening. Late detection was defined as CCHD diagnosis after the birth hospitalization. Deaths potentially avoidable through screening were defined as those that occurred outside a hospital following birth hospitalization discharge and those that occurred within 3 days of an emergency readmission.
For 23% (n =825) of infants, CCHD was not detected during the birth hospitalization. Death occurred among 20% (n =568/2,778) of infants with timely detected CCHD and 8% (n =66/825) of infants with late detected CCHD, unadjusted for clinical characteristics. Potentially preventable deaths occurred in 1.8% (n =15/825) of infants with late detected CCHD (0.4% of all infants with CCHD). In multivariable models adjusted for selected characteristics, late CCHD detection was significantly associated with 52% more admissions, 18% more hospitalized days, and 35% higher inpatient costs during infancy.
Increased CCHD detection at birth hospitals through screening may lead to decreased hospital costs and avoid some deaths during infancy. Additional studies conducted after screening implementation are needed to confirm these findings.
PMCID: PMC4473256  PMID: 24000201
heart defects; congenital; pediatrics; costs and cost analysis; birth defects surveillance
16.  Testing the Feasibility of a National Spina Bifida Patient Registry 
The purpose of this study was to describe the development and early implementation of a national spina bifida (SB) patient registry, the goal of which is to monitor the health status, clinical care, and outcomes of people with SB by collecting and analyzing patient data from comprehensive SB clinics.
Using a web-based, SB-specific electronic medical record, 10 SB clinics collected health-related information for patients diagnosed with myelomeningocele, lipomyelomeningocele, fatty filum, or meningocele. This information was compiled and de-identified for transmission to the Centers for Disease Control and Prevention (CDC) for quality control and analysis.
A total of 2070 patients were enrolled from 2009 through 2011: 84.9% were younger than 18 years of age; 1095 were women; 64.2% were non-Hispanic white; 6.5% were non-Hispanic black or African American; and 24.2% were Hispanic or Latino. Myelomeningocele was the most common diagnosis (81.5%).
The creation of a National Spina Bifida Patient Registry partnership between the CDC and SB clinics has been feasible. Through planned longitudinal data collection and the inclusion of additional clinics, the data generated by the registry will become more robust and representative of the population of patients attending SB clinics in the United States and will allow for the investigation of patient outcomes.
PMCID: PMC4470391  PMID: 23125114
spina bifida; registry; quality improvement; spina bifida clinic; research
17.  Prevalence of Esophageal Atresia among 18 International Birth Defects Surveillance Programs 
The prevalence of esophageal atresia (EA) has been shown to vary across different geographical settings. Investigation of geographical differences may provide an insight into the underlying etiology of EA.
The study population comprised infants diagnosed with EA during 1998 to 2007 from 18 of the 46 birth defects surveillance programs, members of the International Clearinghouse for Birth Defects Surveillance and Research. Total prevalence per 10,000 births for EA was defined as the total number of cases in live births, stillbirths, and elective termination of pregnancy for fetal anomaly (ETOPFA) divided by the total number of all births in the population.
Among the participating programs, a total of 2943 cases of EA were diagnosed with an average prevalence of 2.44 (95% confidence interval [CI], 2.35–2.53) per 10,000 births, ranging between 1.77 and 3.68 per 10,000 births. Of all infants diagnosed with EA, 2761 (93.8%) were live births, 82 (2.8%) stillbirths, 89 (3.0%) ETOPFA, and 11 (0.4%) had unknown outcomes. The majority of cases (2020, 68.6%), had a reported EA with fistula, 749 (25.5%) were without fistula, and 174 (5.9%) were registered with an unspecified code.
On average, EA affected 1 in 4099 births (95% CI, 1 in 3954–4251 births) with prevalence varying across different geographical settings, but relatively consistent over time and comparable between surveillance programs. Findings suggest that differences in the prevalence observed among programs are likely to be attributable to variability in population ethnic compositions or issues in reporting or registration procedures of EA, rather than a real risk occurrence difference.
PMCID: PMC4467200  PMID: 22945024
esophageal atresia; congenital anomalies; prevalence; epidemiology
18.  Maternal Caffeine Consumption and Risk of Congenital Limb Deficiencies 
Animal studies have shown that high doses of caffeine might cause congenital limb deficiencies (LDs); however, no epidemiologic studies have explored this relation.
This case-control study assessed associations between maternal dietary caffeine and congenital LDs using data from the National Birth Defects Prevention Study (NBDPS), with 844 LD cases and 8069 controls from 1997 to 2007. Caffeine intakes from beverages (coffee, tea, and soda) and chocolate combined and by beverage type were examined. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated for subtypes of isolated LDs (no additional major anomalies) and LDs with other major anomalies separately, comparing the odds of 10 to <100, 100 to <200, 200 to <300, and 300+ mg/day total caffeine intake to 0 to <10 mg/day.
All total dietary caffeine intake categories of 10 mg/day and above were marginally associated with odds of all isolated LDs combined (aOR, 1.4–1.7), isolated longitudinal LDs (aOR, 1.2–1.6), and isolated transverse LDs (aOR, 1.3–1.8) compared to the lowest intake category. A dose-response pattern for total dietary caffeine intake was not observed.
A weak increased risk of congenital LDs associated with maternal dietary caffeine consumption was observed in this study; however, risk did not vary by amount of caffeine consumed.
PMCID: PMC4457310  PMID: 22903936
caffeine; coffee; tea; soda; congenital limb deficiencies
19.  Periconceptional Maternal Alcohol Consumption and Neural Tube Defects 
Neural tube defects (NTD)s, which occur when the neural tube fails to close during early gestation, are some of the most common birth defects worldwide. Alcohol is a known teratogen and has been shown to induce NTDs in animal studies, although most human studies have failed to corroborate these results. Using data from the National Birth Defects Prevention Study, associations between maternal reports of periconceptional (1 month prior through 2 months postconception) alcohol consumption and NTDs were examined.
NTD cases and unaffected live born control infants, delivered from 1997 through 2005, were included. Interview reports of alcohol consumption (quantity, frequency, variability, and type) were obtained from 1223 case mothers and 6807 control mothers. Adjusted odds ratios (aOR)s and 95% confidence intervals were estimated using multivariable logistic regression analysis.
For all NTDs combined, most aORs for any alcohol consumption, one or more binge episodes, and different type(s) of alcohol consumed were near unity or modestly reduced (≥0.7
These findings suggest no elevated association between maternal periconceptional alcohol consumption and NTDs. Underreporting of alcohol consumption, due to negative social stigma associated with alcohol consumption during pregnancy, and limited reports for mothers with early pregnancy loss of a fetus with an NTD may have affected the estimated odds ratios. Future studies should aim to increase sample sizes for less prevalent subtypes, reduce exposure misclassification, and improve ascertainment of fetal deaths and elective terminations.
PMCID: PMC4435553  PMID: 23456758
alcohol; birth defects; neural tube defects; pregnancy
Neural tube defects (NTDs), including anencephaly and spina bifida, arise from the failure of neurulation during early embryonic development. Neural tube defects are common birth defects with a heterogenous and multifactorial etiology with interacting genetic and environmental risk factors. Although the mechanisms resulting in failure of neural tube closure are unknown, up to 70% of NTDs can be prevented by maternal folic acid supplementation. However, the metabolic mechanisms underlying the association between folic acid and NTD pathogenesis have not been identified. This review summarizes our current understanding of the mechanisms by which impairments in folate metabolism might ultimately lead to failure of neural tube closure, with an emphasis on untangling the relative contributions of nutritional deficiency and genetic risk factors to NTD pathogenesis.
PMCID: PMC4435943  PMID: 19180567
folate; neural tube defect; metabolism; genetics; thymidylate
Genetic variations affecting neural tube closure along the head result in malformations to the face and brain, posing a significant impact on health care costs and the quality of life. We have established a mouse line from a mutation that arose spontaneously in our wildtype colony that we called tuft. Tuft mice have heritable midline craniofacial defects featuring an anterior lipomatous cephalocele. Whole mount skeletal stains indicated that affected newborns had a broader interfrontal suture where the cephalocele emerged between the frontal bones. Mice with a cephalocele positioned near the rostrum also presented craniofacial malformations such as ocular hypertelorism and midfacial cleft of the nose. Gross and histological examination revealed that the lipomatous cephalocele originated as a fluid filled cyst no earlier than E14.5 while embryos with a midfacial cleft was evident during craniofacial development at E11.5. Histological sections of embryos with a midfacial cleft revealed the cephalic neuroectoderm remained proximal or fused to the frontonasal ectoderm about the closure site of the anterior neuropore, indicating a defect to neural tube closure. We found the neural folds along the rostrum of E9-10.5 embryos curled inward and failed to close as well as embryos with exencephaly and anencephaly at later stages. Whole mount in situ hybridization of anterior markers Fgf8 and Shh indicated closure of the rostral site was compromised in severe cases. We present a model demonstrating how anterior cranial cephaloceles are generated following a defect to neural tube closure and relevance to subsequent craniofacial morphogenesis in the tuft mouse.
PMCID: PMC4426337  PMID: 24931720
anterior cranial cephalocele; midfacial cleft; neural tube defect; encephalocele; exencephaly; anencephaly
Although congenital heart defects (CHDs) are a common and serious group of birth defects, relatively little is known about the causes of these conditions, and there are no established prevention strategies. There is, however, evidence suggesting that the risk of CHDs in general, and conotruncal and related defects (CTRDs) in particular, may be associated with maternal folate status and genetic variants of folate-related genes. Although several folate-related genes have been studied as they relate to CHDs and CTRDs (e.g., MTHFR), others have not been adequately assessed.
Case-parent triads were examined using log-linear analyses to assess the associations between CTRDs and both the genotype inherited by the case and the maternal genotype for the following variants: NAT1 1095C>A, NOS3 894G>T, and TYMS 1494del6. Subgroup analyses were also conducted among cases with classic conotruncal defects and cases with normally related great arteries.
The results provided little evidence that CTRD risk was associated with the genotype inherited by the case for any of the analyzed variants. However, our results suggest that CTRD risk may be associated with the maternal genotype for NOS3 894G>T (p = 0.024 in the subgroup with normally related great arteries) and TYMS 1494del6 (p = 0.048 in the subgroup with classic conotruncal defects). However, these results were not significant after correcting for multiple comparisons.
This study provides further evidence that CTRD risk may be related to variation within folate-pathway genes and suggests that these associations are, at least in part, mediated through the maternal genotype.
PMCID: PMC4404296  PMID: 21254360
folate; NAT1 gene; NOS3 gene; TYMS gene; conotruncal cardiac defects
Valproic acid (VPA) is a commonly prescribed drug for those affected by epilepsy and bipolar disorders. VPA has a well known teratogenic potential, causing a variety of birth defects including neural tube defects (NTDs) and other congenital malformations, when women are treated with this medication during pregnancy. Unfortunately, the mechanism by which VPA is teratogenic remains unknown, although a range of potential mechanisms including histone deacetylase inhibition and folate antagonism have been proposed. The latter is of considerable importance, as clinicians need to know if additional folate supplements can prevent VPA-induced defects.
We herein approach this question experimentally, using enzyme-linked immunosorbent assay assays and cell culture modeling, to demonstrate that VPA serves as a noncompetitive inhibitor of the high affinity folate receptors.
Binding affinities experimentally determined through enzyme-linked immunosorbent assay assays indicate that VPA serves as a noncompetitive substrate that can lessen the ability of the three primary folate forms to bind to the high affinity folate receptors. Tests in HEK293T cells indicate that the membrane-bound folate receptors of VPA treated cells bind significantly lower amounts of folic acid than do untreated cells.
If these data translate to the overall transport and subsequent bioavailability of folates, noncompetitive inhibition of the folate receptors by VPA may serve to lower the bioavailable folates in VPA treated mothers. This represents a novel mechanism by which in utero VPA exposure could be disrupting developmental processes by noncompetitively binding to the folate receptors during embryogenesis, thus inducing the wide range of defects seen in babies born to VPA treated mothers.
PMCID: PMC4396868  PMID: 25066307
valproic acid; folate; vitamin transport; birth defects; teratogens
Bronchopulmonary dysplasia (BPD) is a chronic lung disease of prematurity. Over the years, the BPD phenotype has evolved, but despite various advances in neonatal management approaches, the reduction in the BPD burden is minimal. With the advent of surfactant, glucocorticoids, and new ventilation strategies, BPD has evolved from a disease of structural injury into a new BPD, marked by an arrest in alveolar growth in the lungs of extremely premature infants. This deficient alveolar growth has been associated with a diminution of pulmonary vasculature. Several investigators have described the epithelial/vascular co-dependency and the significant role of crosstalk between vessel formation, alveologenesis, and lung dysplasia’s; hence identification and study of factors that regulate pulmonary vascular emergence and inflammation has become crucial in devising effective therapeutic approaches for this debilitating condition. The potent antiangiogenic and proinflammatory protein Endothelial Monocyte Activating Polypeptide II (EMAP II) has been described as a mediator of pulmonary vascular and alveolar formation and its expression is inversely related to the periods of vascularization and alveolarization in the developing lung. Hence the study of EMAP II could play a vital role in studying and devising appropriate therapeutics for diseases of aberrant lung development, such as BPD. Herein, we review the vascular contribution to lung development and the implications that vascular mediators such as EMAP II have in distal lung formation during the vulnerable stage of alveolar genesis.
PMCID: PMC4280095  PMID: 24619875
AIMP1; SCYE1; bronchopulmonary dysplasia; prematurity
Bronchopulmonary dysplasia (BPD) is a chronic lung disease of extreme prematurity and is defined clinically by dependence on supplemental oxygen due to impaired gas exchange. Optimal gas exchange is dependent on the development of a sufficient surface area for diffusion. In the mammalian lung, rapid acquisition of distal lung surface area is accomplished in neonatal and early adult life by means of vascularization and secondary septation of distal lung airspaces. Extreme preterm birth interrupts secondary septation and pulmonary capillary development and ultimately reduces the efficiency of the alveolar-capillary membrane. Although pulmonary health in BPD infants rapidly improves over the first few years, persistent alveolar-capillary membrane dysfunction continues into adolescence and adulthood. Preventative therapies have been largely ineffective, and therapies aimed at promoting normal development of the air-blood barrier in infants with established BPD remain largely unexplored. The purpose of this review will be: (1) to summarize the histological evidence of aberrant alveolar-capillary membrane development associated with extreme preterm birth and BPD, (2) to review the clinical evidence assessing the long-term impact of BPD on alveolar-capillary membrane function, and (3) to discuss the need to develop and incorporate direct measurements of functional gas exchange into clinically relevant animal models of inhibited alveolar development.
PMCID: PMC3999962  PMID: 24604816
bronchopulmonary dysplasia; mouse; neonatal lung morphogenesis; hyperoxia; lung function; diffusing capacity

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