Pregnancy is now considered to be an important risk factor for new or persistent obesity among women during the childbearing years. High gestational weight gain is the strongest predictor of maternal overweight or obesity following pregnancy. A growing body of evidence also suggests that both high and low gestational weight gains are independently associated with an increased risk of childhood obesity, suggesting that influences occurring very early in life are contributing to obesity onset. In response to these data, the United States Institute of Medicine (IOM) revised gestational weight gain guidelines in 2009 for the first time in nearly two decades. However, less than one-third of pregnant women achieve guideline-recommended gains, with the majority gaining above IOM recommended levels. To date, interventions to optimize pregnancy weight gains have had mixed success. In this paper, we summarize the evidence from human and animal studies linking over-nutrition and under-nutrition in pregnancy to maternal and child obesity. Additionally, we discuss published trials and ongoing interventions to achieve appropriate gestational weight gain as a strategy for obesity prevention in women and their children.
Gestational weight gain; Obesity; Pregnancy; Maternal health; Child health; Postpartum; Fetal growth
Our objective was to examine mothers’ perspectives of obesity-related health behavior recommendations for themselves and their 0–6 month old infants. A health educator conducted 4 motivational counseling calls with 60 mothers of infants during the first 6 months postpartum. Calls addressed 5 behaviors for infants (breastfeeding, introduction of solid foods, sleep, TV, hunger cues), and 4 for mothers (eating, physical activity, sleep, TV). We recorded detailed notes from each call, capturing responsiveness to recommendations and barriers to change. Two independent coders analyzed the notes to identify themes. Mothers in our study were more interested in focusing on their infants’ health behaviors than on their own. While most were receptive to eliminating their infants’ TV exposure, they resisted limiting TV for themselves. There was some resistance to following infant feeding guidelines, and contrary to advice to avoid nursing or rocking babies to sleep, mothers commonly relied on these techniques. Return to work emerged as a barrier to breastfeeding, yet facilitated healthier eating, increased activity, and reduced TV time for mothers. The early postpartum period is a challenging time for mothers to focus on their own health behaviors, but returning to work appears to offer an opportunity for positive changes in this regard. To improve weight-related infant behaviors, interventions should consider mothers’ perceptions of nutrition and physical activity recommendations and barriers to adherence.
Postpartum Women; Infancy; Nutrition; Physical activity; Obesity prevention
To assess the feasibility of a pediatric primary care based intervention to promote healthful behaviors among 0–6 month old infants and their mothers. We enrolled two intervention practices (60 mother-infant pairs) and one usual care control practice (24 pairs) in a non-randomized controlled trial. We completed visits and interviews with 80 (95%) pairs at birth and 6 months. The intervention included (1) brief focused negotiation by pediatricians, (2) motivational counseling by a health educator, and (3) group parenting workshops. We evaluated the intervention effects on infant feeding, sleep duration, TV viewing, and mothers’ responsiveness to satiety cues. Maternal behavioral targets included postpartum diet, physical activity, TV and sleep. At 6 months, fewer intervention than control infants had been introduced to solid foods (57% vs. 82%; P = 0.04), and intervention infants viewed less TV (mean 1.2 vs. 1.5 h/d; P = 0.07). Compared to control infants, intervention infants had larger increases in their nocturnal sleep duration from baseline to follow up (mean increase 1.9 vs. 1.3 h/d; P = 0.05); larger reductions in settling time (mean reduction −0.70 vs. −0.10 h/d; P = 0.02); and larger reductions in hours/day of nighttime wakefulness (mean reduction −2.9 vs. −1.5 h/d; P = 0.08). There were no differences in breastfeeding, response to satiety cues, or maternal health behaviors. A program of brief focused negotiation by pediatricians, individual coaching by health educators using motivational interviewing, and group parenting workshops tended to improve infant feeding, sleep and media exposure, but had less impact on mothers’ own health-related behaviors.
Postpartum women; Infancy; Nutrition; Physical activity; Obesity prevention
In large-scale epidemiology, bloodspot sampling by fingerstick onto filter paper has many advantages, including ease and low costs of collection, processing and transport. We describe the development of an enzyme-linked immunoassay (ELISA) for quantifying insulin from dried blood spots and demonstrate its application in a large trial.
We adapted an existing commercial kit (Mercodia Human Insulin ELISA, 10-1113-01) to quantify insulin from two 3-mm diameter discs (≈6 µL of blood) punched from whole blood standards and from trial samples. Paediatricians collected dried blood spots in a follow-up of 13,879 fasted children aged 11.5 years (interquartile range 11.3–11.8 years) from 31 trial sites across Belarus. We quantified bloodspot insulin levels and examined their distribution by demography and anthropometry.
Mean intra-assay (n = 157) coefficients of variation were 15% and 6% for ‘low’ (6.7 mU/L) and ‘high’ (23.1 mU/L) values, respectively; the respective inter-assay values (n = 33) were 23% and 11%. The intraclass correlation coefficient between 50 paired whole bloodspot versus serum samples, collected simultaneously, was 0.90 (95% confidence interval 0.85 to 0.95). Bloodspot insulin was stable for at least 31 months at −80°C, for one week at +30°C and following four freeze-thaw cycles. Paediatricians collected a median of 8 blood spots from 13,487 (97%) children. The geometric mean insulin (log standard deviation) concentrations amongst 12,812 children were 3.0 mU/L (1.1) in boys and 4.0 mU/L (1.0) in girls and were positively associated with pubertal stage, measures of central and peripheral adiposity, height and fasting glucose.
Our simple and convenient bloodspot assay is suitable for the measurement of insulin in very small volumes of blood collected on filter paper cards and can be applied to large-scale epidemiology studies of the early-life determinants of circulating insulin.
The effect of maternal attempt to lose weight during the postpartum period on later child weight has not been explored. Among 1,044 mother–infant pairs in Project Viva, we estimated longitudinal associations of maternal attempt to lose weight during the postpartum period with child weight and adiposity at age 3 years and examined differences in associations by type of weight loss strategy used. Using covariate-adjusted linear and logistic regression models, we estimated associations before and after adjusting for maternal weight-related variables including prepregnancy BMI. At 6 months postpartum, 53% mothers were trying to lose weight. At age 3 years, mean (s.d.) child BMI z-score was 0.44 (1.01) and 8.9% of children were obese. Children whose mothers were trying to lose weight at 6 months postpartum had higher BMI z-scores (0.30 (95% confidence interval (CI) 0.18, 0.42)) and were more likely to be obese (3.0 (95% CI 1.6, 5.8)) at 3 years of age. Addition of maternal prepregnancy BMI to the models attenuated but did not eliminate the associations seen for BMI z-score (0.24 (95% CI 0.12, 0.36) and obesity (2.4 (95% CI 1.2, 4.7)). Attempting to lose weight by exercising alone was the only weight loss strategy that consistently predicted higher child BMI z-score (0.36 (95% CI 0.14, 0.58)) and odds of obesity (6.0 (95% CI 2.2, 16.5)) at age 3 years. In conclusion, we observed an association between maternal attempt to lose weight at 6 months postpartum, particularly through exercise alone, measured using a single item and child adiposity at age 3 years. This association should be thoroughly examined in future studies.
Fish and shellfish are widely available foods that provide important nutrients, particularly n-3 polyunsaturated fatty acids (n-3 PUFAs), to many populations globally. These nutrients, especially docosahexaenoic acid, confer benefits to brain and visual system development in infants and reduce risks of certain forms of heart disease in adults. However, fish and shellfish can also be a major source of methylmercury (MeHg), a known neurotoxicant that is particularly harmful to fetal brain development. This review documents the latest knowledge on the risks and benefits of seafood consumption for perinatal development of infants. It is possible to choose fish species that are both high in n-3 PUFAs and low in MeHg. A framework for providing dietary advice for women of childbearing age on how to maximize the dietary intake of n-3 PUFAs while minimizing MeHg exposures is suggested.
docosahexaenoic acid; eicosapentaenoic acid; fish; methylmercury; n-3 polyunsaturated fatty acids
Background: Methylmercury (MeHg) is a known neuro-toxicant. Emerging evidence indicates it may have adverse effects on the neuro-logic and other body systems at common low levels of exposure. Impacts of MeHg exposure could vary by individual susceptibility or be confounded by bene-ficial nutrients in fish containing MeHg. Despite its global relevance, synthesis of the available literature on low-level MeHg exposure has been limited.
Objectives: We undertook a synthesis of the current knowledge on the human health effects of low-level MeHg exposure to provide a basis for future research efforts, risk assessment, and exposure remediation policies worldwide.
Data sources and extraction: We reviewed the published literature for original human epidemio-logic research articles that reported a direct biomarker of mercury exposure. To focus on high-quality studies and those specifically on low mercury exposure, we excluded case series, as well as studies of populations with unusually high fish consumption (e.g., the Seychelles), marine mammal consumption (e.g., the Faroe Islands, circumpolar, and other indigenous populations), or consumption of highly contaminated fish (e.g., gold-mining regions in the Amazon).
Data synthesis: Recent evidence raises the possibility of effects of low-level MeHg exposure on fetal growth among susceptible subgroups and on infant growth in the first 2 years of life. Low-level effects of MeHg on neuro-logic outcomes may differ by age, sex, and timing of exposure. No clear pattern has been observed for cardio-vascular disease (CVD) risk across populations or for specific CVD end points. For the few studies evaluating immunologic effects associated with MeHg, results have been inconsistent.
Conclusions: Studies targeted at identifying potential mechanisms of low-level MeHg effects and characterizing individual susceptibility, sexual dimorphism, and non-linearity in dose response would help guide future prevention, policy, and regulatory efforts surrounding MeHg exposure.
birth outcomes; cardio-vascular disease; epidemiology; health outcomes; low-level exposure; metals; methylmercury; neuro-logic outcomes
Background: Diverse perspectives have influenced fish consumption choices.
Objectives: We summarized the issue of fish consumption choice from toxicological, nutritional, ecological, and economic points of view; identified areas of overlap and disagreement among these viewpoints; and reviewed effects of previous fish consumption advisories.
Methods: We reviewed published scientific literature, public health guidelines, and advisories related to fish consumption, focusing on advisories targeted at U.S. populations. However, our conclusions apply to groups having similar fish consumption patterns.
Discussion: There are many possible combinations of matters related to fish consumption, but few, if any, fish consumption patterns optimize all domains. Fish provides a rich source of protein and other nutrients, but because of contamination by methylmercury and other toxicants, higher fish intake often leads to greater toxicant exposure. Furthermore, stocks of wild fish are not adequate to meet the nutrient demands of the growing world population, and fish consumption choices also have a broad economic impact on the fishing industry. Most guidance does not account for ecological and economic impacts of different fish consumption choices.
Conclusion: Despite the relative lack of information integrating the health, ecological, and economic impacts of different fish choices, clear and simple guidance is necessary to effect desired changes. Thus, more comprehensive advice can be developed to describe the multiple impacts of fish consumption. In addition, policy and fishery management inter-ventions will be necessary to ensure long-term availability of fish as an important source of human nutrition.
advisory; economics; fish; methylmercury; nutrition; ocean ecology; poly-chlorinated biphenyls; poly-unsaturated fatty acid; toxicology
Multicenter study designs have several advantages, but the possibility of non-random measurement error resulting from procedural differences between the centers is a special concern. While it is possible to address and correct for some measurement error through statistical analysis, proactive data monitoring is essential to ensure high-quality data collection.
In this article, we describe quality assurance efforts aimed at reducing the effect of measurement error in a recent follow-up of a large cluster-randomized controlled trial through periodic evaluation of intraclass correlation coefficients (ICCs) for continuous measurements. An ICC of 0 indicates the variance in the data is not due to variation between the centers, and thus the data are not clustered by center.
Through our review of early data downloads, we identified several outcomes (including sitting height, waist circumference, and systolic blood pressure) with higher than expected ICC values. Further investigation revealed variations in the procedures used by pediatricians to measure these outcomes. We addressed these procedural inconsistencies through written clarification of the protocol and refresher training workshops with the pediatricians. Further data monitoring at subsequent downloads showed that these efforts had a beneficial effect on data quality (sitting height ICC decreased from 0.92 to 0.03, waist circumference from 0.10 to 0.07, and systolic blood pressure from 0.16 to 0.12).
We describe a simple but formal mechanism for identifying ongoing problems during data collection. The calculation of the ICC can easily be programmed and the mechanism has wide applicability, not just to cluster randomized controlled trials but to any study with multiple centers or with multiple observers.
To examine the association between timing of introduction of solid foods during infancy and obesity at 3 years of age.
We studied 847 children in Project Viva, a prospective pre-birth cohort study. The primary outcome was obesity at 3 years of age (BMI for age and gender ≥95th percentile). The primary exposure was the timing of introduction of solid foods, categorized as <4, 4 to 5, and ≥6 months. We ran separate logistic regression models for infants who were breastfed for at least 4 months (“breastfed”) and infants who were never breastfed or stopped breastfeeding before the age of four months (“formula-fed”), adjusting for child and maternal characteristics, which included change in weight-for-age z score from 0 to 4 months–a marker of early infant growth.
In the first 4 months of life, 568 infants (67%) were breastfed and 279 (32%) were formula-fed. At age 3 years, 75 children (9%) were obese. Among breastfed infants, the timing of solid food introduction was not associated with odds of obesity (odds ratio: 1.1 [95% confidence interval: 0.3–4.4]). Among formula-fed infants, introduction of solid foods before 4 months was associated with a sixfold increase in odds of obesity at age 3 years; the association was not explained by rapid early growth (odds ratio after adjustment: 6.3 [95% confidence interval: 2.3–6.9]).
Among formula-fed infants or infants weaned before the age of 4 months, introduction of solid foods before the age of 4 months was associated with increased odds of obesity at age 3 years.
obesity; infant feeding; complementary foods
Obesity prevalence in the United States has reached an alarming level. Consequently, more young women are entering pregnancy with body mass indices of at least 30 kg/m2. While higher maternal weight entering pregnancy is related to several adverse pregnancy outcomes, some of the strongest and most compelling data to date have linked prepregnancy obesity to gestational diabetes mellitus (GDM). The mechanisms by which excess maternal weight influences metabolic dysfunction in pregnancy are similar to those in obese nonpregnant women; adipocytes are metabolically active and release a number of hormones implicated in insulin resistance. Heavier mothers are also more likely to have higher glucose levels that do not exceed the cutoff for GDM, but nevertheless predict poor perinatal outcomes. Longer-term complications of GDM include increased risk of maternal type 2 diabetes and offspring obesity. Promising intervention studies to decrease the intergenerational cycle of obesity and diabetes are currently underway.
Gestational diabetes mellitus; Obesity; Pregnancy; Postpartum; Maternal health; Child health; Glucose metabolism; Fetal growth; Insulin resistance; Gestational weight gain; Adiposity; Type 2 diabetes mellitus
Few prospective data link early childhood adiposity with asthma-related symptoms.
We sought to examine the associations of weight-for-length (WFL) at age 6 months with incidence of wheezing by age 3 years.
We studied 932 children in a prospective cohort of children. The main outcome was recurrent wheezing, which was defined as parents’ report of wheezing between 2 and 3 years of age plus wheezing in either year 1 or 2 of life. Secondary outcomes included any wheezing from 6 months to 3 years and current asthma. We used multiple logistic regression to examine associations of 6-month WFL z scores with these outcomes.
At 6 months, the infants’ mean WFL z score was 0.68 (SD, 0.94; range −2.96 to 3.24). By age 3 years, 14% of children had recurrent wheezing. After adjustment for a variety of potential confounders, we found that each 1-unit increment in 6-month WFL z score was associated with greater odds of recurrent wheezing (odds ratio [OR], 1.46; 95% CI, 1.11–1.91) and any wheezing (OR, 1.23; 95% CI, 1.03–1.48). We observed a weaker association between 6-month WFL z score and current asthma (OR, 1.22; 95% CI, 0.94–1.59).
Infants with higher WFL z scores at 6 months of age had a greater risk of recurrent wheezing by age 3 years. It is unclear whether the relationship of infant adiposity and early-life wheeze extends to allergic asthma or wheeze that can persist into later childhood. Our findings suggest that early interventions to prevent excess infant adiposity might help reduce children’s risk of asthma-related symptoms.
Asthma; wheeze; adiposity; children; prospective study
To estimate changes over time in birth weight for gestational age and in gestational length among term singleton neonates born from 1990 to 2005.
We used data from the U.S. National Center for Health Statistics for 36,827,828 singleton neonates born at 37–41 weeks of gestation, 1990–2005. We examined trends in birth weight, birth weight for gestational age, large and small for gestational age, and gestational length in the overall population and in a low-risk subgroup defined by maternal age, race or ethnicity, education, marital status, smoking, gestational weight gain, delivery route, and obstetric care characteristics.
In 2005, compared with 1990, we observed decreases in birth weight (−52 g in the overall population, −79 g in a homogenous low-risk subgroup) and large for gestational age birth (−1.4% overall, −2.2% in the homogenous subgroup) that were steeper after 1999 and persisted in regression analyses adjusted for maternal and neonate characteristics, gestational length, cesarean delivery, and induction of labor. Decreases in mean gestational length (−0.34 weeks overall) were similar regardless of route of delivery or induction of labor.
Recent decreases in fetal growth among U.S., term, singleton neonates were not explained by trends in maternal and neonatal characteristics, changes in obstetric practices, or concurrent decreases in gestational length.
LEVEL OF EVIDENCE
To make recommendations for future clinical, public health, and research practices for women with abnormal glucose tolerance during pregnancy, we reviewed the latest evidence regarding rates of postpartum diabetes screening and types of screening tests.
We searched PubMed for journal articles published from January 2008 through December 2010 that reported on postpartum screening and studies designed to prevent progression to type 2 diabetes among women with gestational diabetes mellitus (GDM). Two authors independently reviewed titles and abstracts from 265 articles.
From 34% to 73% of women with GDM completed postpartum glucose screening. Predictors of higher screening rates included older age, nulliparity, and higher income or education. Screening rates varied by race/ethnicity; Asian women were more likely to be screened than were other racial/ethnic minorities. Women who received prenatal care, who were treated with insulin during pregnancy, or who completed a 6-week postpartum visit were also more likely to receive screening. A moderate proportion of women screened had type 2 diabetes (1.2%-4.5%) or prediabetes (12.2%-36.0%).
Rates of postpartum screening among women with a history of GDM are low; only half of women in most populations are screened. Our findings can inform future screening initiatives designed to overcome barriers to screening for both providers and patients. Well-designed lifestyle interventions specific to women with a history of abnormal glucose tolerance during pregnancy and also studies to determine the efficacy and safety of pharmacological interventions will be important to help prevent progression to diabetes among these high-risk women.
Although obesity screening and treatment are recommended by the US Preventive Services Task Force, 1 in 5 women are obese when they conceive. Women are at risk for complications of untreated obesity particularly during the reproductive years and may benefit from targeted screening. Risks of obesity and potential benefits of intervention in this population are well characterized. Rates of adverse pregnancy outcomes including gestational diabetes, preeclampsia, cesarean delivery, and stillbirth increase as maternal body mass index increases. Offspring risks include higher rates of congenital anomalies, abnormal intrauterine growth, and childhood obesity. Observational data suggest that weight loss may reduce risks of obesity-related pregnancy complications. Although obesity screening has not been studied in women of reproductive age, the effect of obesity and the potential for significant maternal and fetal benefits make screening of women during the childbearing years an essential part of the effort to reduce the impact of the obesity epidemic.
The goal of this paper was to determine predictors of having a weight gain goal in early pregnancy. In 2008, we administered a 48-item survey to 249 pregnant women attending obstetric visits. We examined predictors of women having a goal concordant or discordant with 1990 Institute of Medicine (IOM) guidelines, vs. no goal, using binary and multinomial logistic regression. Of the 292 respondents, 116 (40%) had no gestational weight gain goal, 112 (39%) had a concordant goal and 61 (21%) had a goal discordant with IOM guidelines. Predictors of a guideline-concordant goal, vs. no goal, included sugar sweetened beverage consumption < vs. ≥ 1 serving per week (OR = 2.4, 95%CI: 1.1, 5.7), physical activity ≥ vs. <2.5 h per week (OR = 3.6, 95%CI: 1.7, 7.5), agreeing that `I tried to keep weight down not to look pregnant' (OR = 14.3, 95%CI: 1.4, 140.5). Other predictors only of having a discordant goal (vs. no goal) included agreeing that `as long as I am eating well, I don't care how much I gain' (OR = 0.3, 95%CI: 0.2, 0.8) and agreeing that `if I gain too much weight one month, I try to keep from gaining the next' (OR = 4.1, 95%CI: 1.6, 10.4). Women whose doctors recommended weight gains consistent with IOM guidelines were more likely to have a concordant goal (vs. no goal) (OR = 5.3, 95%CI: 1.5, 18.6). Engaging in healthy behaviors and having health providers offer IOM weight gain recommendations may increase the likelihood of having a concordant gestational weight gain goal, which, in turn, is predictive of actual weight gains that fall within IOM guidelines.
Pregnancy; Weight gain goal; Behavioral and maternal characteristics
Background & Aims
The purpose of this study was to determine the effects of total energy intake, macronutrient intake, and maternal adherence to Mediterranean diet or Alternative Healthy Eating Index (AHEI) on cord blood leptin and adiponectin levels, which have been associated with childhood adiposity.
We used multivariable linear regression to assess associations of maternal diet, averaged over 1st and 2nd trimesters, with cord blood adipokines of 780 women from the prospective cohort study Project Viva.
Mean (SD) energy intake during pregnancy was 2135 (596) kcal. Mean (SD) cord blood levels of leptin and adiponectin were 9.0 (6.6) ng/ml and 28.6 (6.7) μg/ml, respectively. Neither closer adherence to a Mediterranean/AHEI pattern diet nor energy intake was associated with either cord blood leptin or adiponectin. Protein intake was associated with both marginally lower leptin (−0.22 ng/ml [95% CI −0.41, −0.02] for each 1% of energy) and adiponectin (−0.25 μg/ml [95% CI −0.48, −0.02]).
Closer adherence to a Mediterranean/AHEI pattern diet during pregnancy was not associated with cord blood leptin or adiponectin. Maternal protein intake was weakly but significantly associated with lower cord blood leptin and adiponectin.
leptin; adiponectin; Mediterranean diet; Alternative healthy eating index (AHEI); Protein intake
Both maternal pre-pregnancy obesity and excessive gestational weight gain are increasing in prevalence and associated with a number of adverse pregnancy outcomes for both mother and child. Observational studies regarding physical activity in pregnancy have found reduced weight gain in active mothers, as well as reduced risk of adverse pregnancy outcomes. There is however a lack of high quality, randomized controlled trials on the effects of regular exercise training in pregnancy, especially those with a pre-pregnancy body mass index (BMI) at or above 30 kg/m2.
We are conducting a randomised, controlled trial in Norway with two parallel arms; one intervention group and one control group. We will enroll 150 previously sedentary, pregnant women with a pre-pregnancy BMI at or above 30 kg/m2. The intervention group will meet for organized exercise training three times per week, starting in gestation week 14 (range 12-16). The control group will get standard antenatal care. The main outcome measure will be weight gain from baseline to delivery. Among the secondary outcome measures are changes in exercise capacity, endothelial function, physical activity level, body composition, serum markers of cardiovascular risk, incontinence, lumbopelvic pain and cardiac function from baseline to gestation week 37 (range 36-38). Offspring outcome measures include anthropometric variables at birth, Apgar score, as well as serum markers of inflammation and metabolism in cord blood.
The results of this trial will provide knowledge about effects of regular exercise training in previously sedentary, obese pregnant women. If the program proves effective in reducing gestational weight gain and adverse pregnancy outcomes, such programs should be considered as part of routine pregnancy care for obese women.
We examined the association of prenatal depressive symptoms at mid-pregnancy with child cognition at age 3 years in Project Viva, a pre-birth cohort study of 1030 mother-child pairs in eastern Massachusetts. We measured maternal depressive symptoms using the Edinburgh Postnatal Depression Scale (EPDS), a self-report measure validated for use during pregnancy. Measures of child cognition included the Peabody Picture Vocabulary Test (PPVT) and the Wide Range Achievement of Visual Motor Abilties (WRAVMA). At mid-pregnancy, 81 mothers (7.9%) scored 13 or above on the EPDS, indicating probable depression. In the unadjusted model, children born to mothers with prenatal depressive symptoms had PPVT scores that were 3.8 points lower [95% confidence interval (CI) −7.1, −0.5]. With adjustment for sociodemographics, the association substantially attenuated [adjusted β for PPVT score = −0.7 (95% CI −3.6, 2.3)]. In both unadjusted and multivariable models, prenatal depressive symptoms were not associated with WRAVMA scores [adjusted β for total WRAVMA score = −0.5 (95% CI −3.0, 2.1)]. We found no evidence to suggest that maternal prenatal depression is independently associated with early child cognition.
It is suggested that maternal adiposity has a stronger association with offspring adiposity than does paternal adiposity. Furthermore, a recent small study reported gender assortment in parental-offspring adiposity associations. We aimed to examine these associations in one of the largest studies to date using data from a low-middle income country that has recently undergone a major political and economic transition.
Methods and Principal Findings
In a cross-sectional study of 12,181 parental-offspring trios from Belarus (mean age (SD) of mothers 31.7 (4.9), fathers 34.1 (5.1) and children 6.6 (0.3) at time of assessment), we found positive graded associations of mother's and father's BMI with offspring adiposity. There was no evidence that these associations differed between mothers and fathers. For example, the odds ratio of offspring overweight or obesity (based on BMI) comparing obese and overweight mothers to normal weight mothers was 2.03 (95%CI 1.77, 2.31) in fully adjusted models; the equivalent result for father's overweight/obesity was 1.81 (1.58, 2.07). Equivalent results for offspring being in the top 10% waist circumference were 1.91 (1.67, 2.18) comparing obese/overweight to normal weight mothers and 1.72 (1.53, 1.95) comparing obese/overweight to normal weight fathers. Similarly, results for offspring being in the top 10% of percent fat mass were 1.58 (1.36, 1.84) and 1.76 (1.49, 2.07), for mother's and father's obese/overweight exposures respectively. There was no strong or consistent evidence of gender assortment - i.e. associations of maternal adiposity exposures with offspring outcomes were similar in magnitude for their daughters compared to equivalent associations in their sons and paternal associations were also similar in sons and daughters.
These findings suggest that genetic and/or shared familial environment explain family clustering of adiposity. Interventions aimed at changing overall family lifestyle are likely to be important for population level obesity prevention.
Maternal obesity is associated with adverse pregnancy outcomes. To improve outcomes, obstetric providers must effectively evaluate and manage their obese pregnant patients. We sought to determine the knowledge, attitudes, and practice patterns of obstetric providers regarding obesity in pregnancy.
In 2007–2008, we surveyed 58 practicing obstetricians, nurse practitioners, and certified nurse-midwives at a multispecialty practice in Massachusetts. We administered a 26-item questionnaire that included provider self-reported weight, sociodemographic characteristics, knowledge, attitudes, and management practices. We created an 8-point score for adherence to 8 practices recommended by the American College of Obstetricians and Gynecologists (ACOG) for the management of obese pregnant women.
Among the respondents, 37% did not correctly report the minimum body mass index (BMI) for diagnosing obesity, and most reported advising gestational weight gains that were discordant with 1990 Institute of Medicine (IOM) guidelines, especially for obese women (71%). The majority of respondents almost always recommended a range of weight gain (74%), advised regular physical activity (74%), or discussed diet (64%) with obese mothers, but few routinely ordered glucose tolerance testing during the first trimester (26%), planned anesthesia referrals (3%), or referred patients to a nutritionist (14%). Mean guideline adherence score was 3.4 (SD 1.9, range 0–8). Provider confidence (β = 1.0, p = 0.05) and body satisfaction (β = 1.5, p = 0.02) were independent predictors of higher guideline adherence scores.
Few obstetric providers were fully compliant with clinical practice recommendations, defined obesity correctly, or recommended weight gains concordant with IOM guidelines. Provider personal factors were the strongest correlates of self-reported management practices. Our findings suggest a need for more education around BMI definitions and weight gain guidelines, along with strategies to address provider personal factors, such as confidence and body satisfaction, that may be important predictors of adherence to recommendations for managing obese pregnant women.
To study associations of maternal gestational weight gain with offspring weight status in adolescence.
We surveyed 11,994 adolescents aged 9–14 enrolled in the Growing Up Today Study cohort and their mothers, members of the Nurses’ Health Study II. We used multivariable linear and logistic regression to study associations of gestational weight gain with offspring adiposity.
Mean (SD) gestational weight gain was 31.5 (11.2) pounds and offspring BMI z-score (BMI standardized for age and sex) was 0.15 (1.0) units; 6.5% of adolescents were obese (BMI greater than or equal to the 95th percentile). Gestational gain was linearly associated with adolescent adiposity: compared with 20–24 pounds, gain less than 10 pounds was associated with child BMI z-score 0.25 units lower (95% confidence interval [CI]: −0.47, −0.04), and gain greater than or equal to 45 pounds with BMI z-score 0.18 units higher (95% CI: 0.11, 0.25). Compared with women with adequate gain according to 1990 Institute of Medicine guidelines, women with excessive gain had children with higher BMI z-scores (0.14 units, 95% CI: 0.09, 0.18) and risk of obesity (odds ratio 1.42, 95% CI: 1.19, 1.70). The predicted prevalence of term low birth weight declined modestly across the range of gain (2% for gain less than 10 pounds, 1% for gain greater than or equal to 45 pounds), whereas term high birth weight increased dramatically with higher gain (10% for gain less than 10 pounds, 35% for gain of greater than or equal to 45 pounds).
Gestational weight gain is directly associated with BMI and risk of obesity in adolescence. Revised gestational weight gain guidelines should account for influences on child weight.
Shorter sleep duration is linked to obesity, coronary artery disease, and diabetes. Whether sleep deprivation during the postpartum period affects maternal postpartum weight retention remains unknown. This study examined the association of sleep at 6 months postpartum with substantial postpartum weight retention (SPPWR), defined as 5 kg or more above pregravid weight at 1 year postpartum. The authors selected 940 participants in Project Viva who enrolled during early pregnancy from 1999 to 2002. Logistic regression models estimated odds ratios of SPPWR for sleep categories, controlling for sociodemographic, prenatal, and behavioral attributes. Of the 940 women, 124 (13%) developed SPPWR. Sleep distributions were as follows: 114 (12%) women slept ≥5 hours/day, 280 (30%) slept 6 hours/day, 321 (34%) slept 7 hours/day, and 225 (24%) slept≤8 hours/day. Adjusted odds ratios of SPPWR were 3.13 (95% confidence interval (CI): 1.42, 6.94) for ≤5 hours/day, 0.99 (95% CI: 0.50, 1.97) for 6 hours/day, and 0.94 (95% CI: 0.50, 1.78) for ≥8 hours/day versus 7 hours/day (p = 0.012). The adjusted odds ratio for SPPWR of 2.05 (95% CI: 1.11, 3.78) was twofold greater (p = 0.02) for a decrease in versus no change in sleep at 1 year postpartum. Sleeping ≤5 hours/day at 6 months postpartum was strongly associated with retaining ≥5 kg at 1 year postpartum. Interventions to prevent postpartum obesity should consider strategies to attain optimal maternal sleep duration.
cohort studies; obesity; postpartum period; pregnancy; prospective studies; sleep; weight gain; women's health
The authors investigated the rate of gestational weight gain associated with the lowest combined risk of 5 short- and longer-term maternal and child health outcomes for 2,012 mother-child pairs recruited in 1999–2002 into Project Viva, a prebirth cohort study in Massachusetts. Within each maternal prepregnancy body mass index (BMI, kg/m2) stratum, they performed a logistic regression analysis predicting all 5 outcomes, from which they determined the rate of gain at which average predicted prevalence of the adverse outcomes was the lowest. The mean rate of total gestational weight gain was 0.39 kg/week (standard deviation, 0.14). The prevalence of small for gestational age was 6%, large for gestational age was 14%, preterm delivery was 7%, substantial postpartum weight retention was 16%, and child obesity was 10%. The lowest predicted outcome prevalence occurred with a 0.28-kg/week gain for women whose BMI was 18.5–24.9, a 0.03-kg/week loss for a BMI of 25.0–29.9, and a 0.19-kg/week loss for a BMI of ≥30.0 kg/m2—the lowest observed weight changes in overweight and obese women. For normal-weight and overweight women, lowest-risk gains varied modestly with adjustment for maternal characteristics and with different outcome weightings. For obese women, the lowest-risk weight change was weight loss in all models. Recommendations for gestational weight gain for obese women should be revised.
fetal development; obesity; pregnancy; premature birth; weight gain
We sought to identify modifiable risk factors for excessive gestational weight gain (GWG).
We assessed associations of diet and physical activity with excessive gain among 1388 women from the Project Viva cohort study.
379 (27%) of women were overweight (BMI>=26kg/m2) and 703 (51%) experienced excessive GWG, according to Institute of Medicine guidelines. In multivariable logistic regression models, we found that intake of total energy (OR 1.10, 95%CI 1.00–1.22, per 500 kcal/day), dairy (1.08, 95%CI 1.00–1.17, per serving/day), and fried foods (OR 3.47, 95%CI 0.91–13.24, per serving/day) were directly associated with excessive GWG. First trimester vegetarian diet (0.46, 95%CI 0.28–0.78) and mid-pregnancy walking (0.91, 95%CI 0.82–1.00, per half-hour/day) and vigorous physical activity (0.76, 95%CI 0.60–0.97, per half-hour/day) were inversely associated with excessive GWG.
Healthful diet and greater physical activity are associated with reduced risk for excessive gestational weight gain.
diet; obesity; physical activity; pregnancy; weight gain