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Background: The current Institute of Medicine (IOM) pregnancy weight gain guidelines were developed using the best available evidence but were limited by substantial knowledge gaps. Some have raised concern that the guidelines for individuals affected by overweight or obesity are too high and contribute to short- and long-term complications for the mother and child., Objectives: To determine the association between pregnancy weight gain below the lower limit of the current IOM recommendations and risk of 10 adverse maternal and child health outcomes among individuals with overweight and obesity., Methods: We used data from a prospective cohort study of United States nulliparae with prepregnancy overweight (n = 955) or obesity (n = 897) followed from the first trimester to 2-7 y postpartum. We used multivariable Poisson regression to relate pregnancy weight gain z-scores with a severity-weighted composite outcome consisting of ≥1 of 10 adverse outcomes (gestational diabetes, preeclampsia, unplanned cesarean delivery, maternal postpartum weight increase >10 kg, maternal postpartum metabolic syndrome, infant death, stillbirth, preterm birth, small-for-gestational age birth, and childhood obesity)., Results: Pregnancy weight gain z-scores below, within, and above the IOM-recommended ranges occurred in 5%, 13%, and 80% of pregnancies with overweight and 17%, 13%, and 70% of pregnancies with obesity. There was a positive association between pregnancy weight gain z-scores and all adverse maternal outcomes, childhood obesity, and the composite outcome. Pregnancy weight gain z-scores below the lower limit of the recommended ranges (<6.8 kg for overweight, <5 kg for obesity) were not associated with the severity-weighted composite outcome. For example, compared with the lower limit, adjusted rate ratios (95% confidence interval) for z-scores of -2 standard deviations in pregnancies with overweight (equivalent to 3.6 kg at 40 wk) and obesity (-2.8 kg at 40 wk) were 0.99 (95% confidence interval [CI]: 0.91, 1.06) and 0.97 (95% CI: 0.87, 1.07)., Conclusions: These findings support arguments to decrease the lower limit of recommended weight gain ranges in these prepregnancy body mass index groups., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: There are concerns that current gestational weight gain recommendations for women with obesity are too high and that guidelines should differ on the basis of severity of obesity. In this study we investigated the safety of gestational weight gain below current recommendations or weight loss in pregnancies with obesity, and evaluated whether separate guidelines are needed for different obesity classes., Methods: In this population-based cohort study, we used electronic medical records from the Stockholm-Gotland Perinatal Cohort study to identify pregnancies with obesity (early pregnancy BMI before 14 weeks' gestation ≥30 kg/m 2 ) among singleton pregnancies that delivered between Jan 1, 2008, and Dec 31, 2015. The pregnancy records were linked with Swedish national health-care register data up to Dec 31, 2019. Gestational weight gain was calculated as the last measured weight before or at delivery minus early pregnancy weight (at <14 weeks' gestation), and standardised for gestational age into z-scores. We used Poisson regression to assess the association of gestational weight gain z-score with a composite outcome of: stillbirth, infant death, large for gestational age and small for gestational age at birth, preterm birth, unplanned caesarean delivery, gestational diabetes, pre-eclampsia, excess postpartum weight retention, and new-onset longer-term maternal cardiometabolic disease after pregnancy, weighted to account for event severity. We calculated rate ratios (RRs) for our composite adverse outcome along the weight gain z-score continuum, compared with a reference of the current lower limit for gestational weight gain recommended by the US Institute of Medicine (IOM; 5 kg at term). RRs were adjusted for confounding factors (maternal age, height, parity, early pregnancy BMI, early pregnancy smoking status, prepregnancy cardiovascular disease or diabetes, education, cohabitation status, and Nordic country of birth)., Findings: Our cohort comprised 15 760 pregnancies with obesity, followed up for a median of 7·9 years (IQR 5·8-9·4). 11 667 (74·0%) pregnancies had class 1 obesity, 3160 (20·1%) had class 2 obesity, and 933 (5·9%) had class 3 obesity. Among these pregnancies, 1623 (13·9%), 786 (24·9%), and 310 (33·2%), respectively, had weight gain during pregnancy below the lower limit of the IOM recommendation (5 kg). In pregnancies with class 1 or 2 obesity, gestational weight gain values below the lower limit of the IOM recommendation or weight loss did not increase risk of the adverse composite outcome (eg, at weight gain z-score -2·4, corresponding to 0 kg at 40 weeks: adjusted RR 0·97 [95% CI 0·89-1·06] in obesity class 1 and 0·96 [0·86-1·08] in obesity class 2). In pregnancies with class 3 obesity, weight gain values below the IOM limit or weight loss were associated with reduced risk of the adverse composite outcome (eg, adjusted RR 0·81 [0·71-0·89] at weight gain z-score -2·4, or 0 kg)., Interpretation: Our findings support calls to lower or remove the lower limit of current IOM recommendations for pregnant women with obesity, and suggest that separate guidelines for class 3 obesity might be warranted., Funding: Karolinska Institutet and the Eunice Kennedy Shriver National Institute of Child Health and Human Development., Competing Interests: Declaration of interests OS declares that he is the co-founder and co-owner of a Swedish pregnancy app, One Million Babies. KJ, LMB, and JAH are advising on a WHO initiative to create global pregnancy weight gain standards, for which KJ and JAH have received financial support for meeting attendance or travel, and JAH has received consulting fees. The views expressed in this study do not reflect the views of WHO. BA declares no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: The periconceptional period is a critical window for the origins of adverse pregnancy and birth outcomes, yet little is known about the dietary patterns that promote perinatal health., Objective: We used machine learning methods to determine the effect of periconceptional dietary patterns on risk of preeclampsia, gestational diabetes, preterm birth, small-for-gestational-age (SGA) birth, and a composite of these outcomes., Methods: We used data from 8259 participants in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (8 US medical centers, 2010‒2013). Usual daily periconceptional intake of 82 food groups was estimated from a food frequency questionnaire. We used k-means clustering with a Euclidean distance metric to identify dietary patterns. We estimated the effect of dietary patterns on each perinatal outcome using targeted maximum likelihood estimation and an ensemble of machine learning algorithms, adjusting for confounders including health behaviors and psychological, neighborhood, and sociodemographic factors., Results: The 4 dietary patterns that emerged from our data were identified as "Sandwiches and snacks" (34% of the sample); "High fat, sugar, and sodium" (29%); "Beverages, refined grains, and mixed dishes" (21%); and "High fruits, vegetables, whole grains, and plant proteins" (16%). One-quarter of pregnancies had preeclampsia (8% incidence), gestational diabetes (5%), preterm birth (8%), or SGA birth (8%). Compared with the "High fat, sugar, and sodium" pattern, there were 3.3 to 4.3 fewer cases of the composite adverse outcome per 100 pregnancies among participants following the "Beverages, refined grains and mixed dishes" pattern (risk difference -0.043; 95% confidence interval -0.078, -0.009), "High fruits, vegetables, whole grains and plant proteins" pattern (-0.041; 95% confidence interval -0.078, -0.004), and "Sandwiches and snacks" pattern (-0.033; 95% confidence interval -0.065, -0.002)., Conclusions: Our results highlight that there are a variety of periconceptional dietary patterns that are associated with perinatal health and reinforce the negative health implications of diets high in fat, sugars, and sodium., (Copyright © 2023 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Background: The Institute of Medicine pregnancy weight gain guidelines were developed without evidence linking high weight gain to maternal cardiometabolic disease and child obesity. The upper limit of current recommendations may be too high for the health of the pregnant individual and child., Objectives: The aim of this study was to identify the range of pregnancy weight gain for pregnancies within a normal body mass index (BMI) range that balances the risks of high and low weight gain by simultaneously considering 10 different health conditions., Methods: We used data from an United States prospective cohort study of nulliparae followed until 2 to 7 y postpartum (N = 2344 participants with a normal BMI). Pregnancy weight gain z-score was the main exposure. The outcome was a composite consisting of the occurrence of ≥1 of 10 adverse health conditions that were weighted for their seriousness. We used multivariable Poisson regression to relate weight gain z-scores with the weighted composite outcome., Results: The lowest risk of the composite outcome was at a pregnancy weight gain z-score of -0.6 SD (standard deviation) (equivalent to 13.1 kg at 40 wk). The weight gain ranges associated with no more than 5%, 10%, and 20% increase in risks were -1.0 to -0.2 SD (11.2-15.3 kg), -1.4 to 0 SD (9.4-16.4 kg), and -2.0 to 0.4 SD (7.0-18.9 kg). When we used a lower threshold to define postpartum weight increase in the composite outcome (>5 kg compared with >10 kg), the ranges were 1.6 to -0.7 SD (8.9-12.6 kg), -2.2 to -0.3 SD (6.3-14.7 kg), and ≤0.2 SD (≤17.6 kg). Compared with the ranges of the current weight gain guidelines (-0.9 to -0.1 SD, 11.5-16 kg), the lower limits from our data tended to be lower while upper limits were similar or lower., Conclusions: If replicated, our results suggest that policy makers should revisit the recommended pregnancy weight gain range for individuals within a normal BMI range., (Copyright © 2023 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Background: Diets dense in fruits and vegetables are associated with a reduced risk of preeclampsia, but pathways underlying this relationship are unclear. Dietary antioxidants may contribute to the protective effect., Objective: We determined the extent to which the effect of dietary fruit and vegetable density on preeclampsia is because of high intakes of dietary vitamin C and carotenoids., Methods: We used data from 7572 participants in the Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be (8 United States medical centers, 2010‒2013). Usual daily periconceptional intake of total fruits and total vegetables was estimated from a food frequency questionnaire. We estimated the indirect effect of ≥2.5 cups/1000 kcal of fruits and vegetables through vitamin C and carotenoid on the risk of preeclampsia. We estimated these effects using targeted maximum likelihood estimation and an ensemble of machine learning algorithms, adjusting for confounders, including other dietary components, health behaviors, and psychological, neighborhood, and sociodemographic factors., Results: Participants who consumed ≥2.5 cups of fruits and vegetables per 1000 kcal were less likely than those who consumed <2.5 cups/1000 kcal to develop preeclampsia (6.4% compared with 8.6%). After confounder adjustment, we observed that higher fruit and vegetable density was associated with 2 fewer cases of preeclampsia (risk difference: -2.0; 95% CI: -3.9, -0.1)/100 pregnancies compared with lower density diets. High dietary vitamin C and carotenoid intake was not associated with preeclampsia. The protective effect of high fruit and vegetable density on the risk of preeclampsia and late-onset preeclampsia was not mediated through dietary vitamin C and carotenoids., Conclusions: Evaluating other nutrients and bioactives in fruits and vegetables and their synergy is worthwhile, along with characterizing the effect of individual fruits or vegetables on preeclampsia risk., (Copyright © 2023 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Background: Racism is a key determinant of perinatal health disparities. Poor diet may contribute to this effect, but research on racism and dietary patterns is limited., Objective: We aimed to describe the relation between experiences of racial discrimination and adherence to the 2015‒2020 Dietary Guidelines for Americans., Methods: We used data from a prospective pregnancy cohort study conducted at 8 United States medical centers (2010‒2013). At 6‒13 weeks of gestation, 10,038 nulliparous people with singleton pregnancies were enrolled. Participants completed a Block food frequency questionnaire, assessing usual diet in the 3 mo around conception, and the Krieger Experiences of Discrimination Scale, assessing the number of situational domains (e.g., at school and on the street) in which participants ever experienced racial discrimination. Alignment of dietary intake with the 2015-2020 Dietary Guidelines for Americans was assessed using the Healthy Eating Index (HEI)-2015., Results: The study showed that 49%, 44%, 35%, and 17% of the Asian, Black, Hispanic, and White participants reported experiences of racial discrimination in any domain. Most participants experienced discrimination in 1 or 2 situational domains. There were no meaningful differences in HEI-2015 total or component scores in any racial or ethnic group according to count of self-reported domains in which individuals experienced discrimination. For example, mean total scores were 57‒59 among Black, 61‒66 among White, 61‒63 among Hispanic, and 66‒69 among Asian participants across the count of racial discrimination domains., Conclusions: This null association stresses the importance of going beyond interpersonal racial discrimination to consider the institutions, systems, and practices affecting racialized people to eliminate persistent inequalities in diet and perinatal health., (Copyright © 2023 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Purpose: A strength of SuperLearner is that it may accommodate key interactions between model variables without a priori specification. In prior research, protective associations between fruit intake and preeclampsia were stronger when estimated using SuperLearner with targeted maximum likelihood estimation (TMLE) compared with multivariable logistic regression without any interaction terms. We explored whether heterogeneity (i.e., differences in the effect estimate due to interactions between fruit intake and covariates) may partly explain differences in estimates from these two models., Methods: Using a U.S. prospective pregnancy cohort (2010-2013, n = 7781), we estimated preeclampsia risk differences (RDs) for higher versus lower fruit density using multivariable logistic regression and included two-way statistical interactions between fruit density and each of the 25 model covariates. We compared the RDs with those from SuperLearner with TMLE (gold standard) and logistic regression with no interaction., Results: From the logistic regression models with two-way statistical interactions, 48% of the preeclampsia RDs were ≤-0.02 (closer to SuperLearner with TMLE estimate); 40% equaled -0.01 (same as logistic regression with no interaction estimate); the minority of RDs were at or crossed the null., Conclusions: Our exploratory analysis provided preliminary evidence that heterogeneity may partly explain differences in estimates from logistic regression versus SuperLearner with TMLE., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Lisa Bodnar and Ashley Naimi report financial support was provided by the National Institute of Child Health and Human Development., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Adherence to the Dietary Guidelines for Americans is often assessed using the Healthy Eating Index (HEI). The HEI total score reflects overall diet quality, with all aspects equally important. Using the traditional weighting scheme for the HEI, all components are generally weighted equally in the total score. However, there is limited empirical basis for applying the traditional weighting for pregnancy specifically., Objectives: We aimed to assess associations between the 12 HEI-2010 component scores and select pregnancy outcomes., Methods: The Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be was a prospective pregnancy cohort (US multicenter, 2010-2013). Participants enrolled in the study between 6 and 13 weeks of gestation. An FFQ assessed usual dietary intake 3 months prior to pregnancy (n = 7880). Scores for the HEI-2010 components were assigned using prespecified standards based on densities (standard units per 1000 kcal) of relevant food groups for most components, a ratio (PUFAs and MUFAs to SFAs) for fatty acids, and the contribution to total energy for empty calories. Using binomial regression, we estimated risk differences between each component score and cases of small-for-gestational age (SGA) birth, preterm birth, preeclampsia, and gestational diabetes, controlling for total energy and scores for the other HEI-2010 components., Results: Higher scores for greens and beans and total vegetables were associated with fewer cases of SGA birth, preterm birth, and preeclampsia. For instance, every 1-unit increase in the greens and beans score was associated with 1.2 fewer SGA infants (95% CI, 0.7-1.7), 0.7 fewer preterm births (95% CI, 0.3-1.1), and 0.7 fewer preeclampsia cases (95% CI, 0.2-1.1) per 100 deliveries. For gestational diabetes, the associations were null., Conclusions: Vegetable-rich diets were associated with fewer cases of SGA birth, preterm birth, and preeclampsia, controlling for overall diet quality. Examination of the equal weighting of the HEI components (and underlying guidance) is needed for pregnancy., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society for Nutrition.)

Purpose: Researchers are interested in studying longitudinal patterns of gestational weight gain, yet this requires daily/weekly weights, and maternal weight is measured only during prenatal visits. We evaluated the relative accuracy and precision of methods for estimating maternal weight gain between prenatal visits among twin and singleton pregnancies., Methods: We analyzed cohorts of dichorionic twin and singleton pregnancies delivered from 1998-2013 in Pittsburgh, Pennsylvania. We mimicked a typical study by retaining pre-pregnancy, first prenatal visit, glucose screening visit, and delivery weights, using these to fit interpolation models, estimating weight throughout pregnancy using 16 different methods, and calculating the difference in kilograms between predicted and measured values among remaining weights. We evaluated the performance of each model by calculating root mean squared error (RMSE)., Results: RMSE ranged from 1.55 to 6.09 kg in twins (n = 2067) and 1.45 to 4.87 kg in singletons (n = 7331). The most accurate and precise methods incorporated restricted cubic splines, random intercepts and slopes for pregnancy, and internal knots demarcating trimesters/quantiles (RMSE = 1.55/1.56 kg in twins, 1.45/1.45 kg in singletons), while individual-level linear interpolation between proximal measurements also performed well., Conclusions: Accuracy and precision of methods for estimating maternal weight gain between measurements differed by model, and were best among individually-tailored and flexible models., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: The contribution of substance use disorders to the burden of severe maternal morbidity in the United States is poorly understood. The objective was to estimate the independent association between substance use disorders during pregnancy and risk of severe maternal morbidity., Methods: Retrospective analysis of a weighted 53.4 million delivery hospitalizations from 2003 to 2016 among females aged>18 in the National Inpatient Sample. We constructed measures of substance use disorders using diagnostic codes for cannabis, opioids, and stimulants (amphetamines or cocaine) abuse or dependence during pregnancy. The outcome was the presence of any of the 21 CDC indicators of severe maternal morbidity. Using weighted multivariable logistic regression, we estimated the association between substance use disorders and adjusted risk of severe maternal morbidity. Because older age at delivery is predictive of severe maternal morbidity, we tested for effect modification between substance use and maternal age by age group (18-34 y vs >34 y)., Results: Pregnant women with an opioid use disorder had an increased risk of severe maternal morbidity compared with women without an opioid use disorder (18-34 years: aOR: 1.51; 95 % CI: 1.41,1.61, >34 years: aOR: 1.17; 95 % CI: 1.00,1.38). Compared with their counterparts without stimulant use disorders, pregnant women with a simulant use disorder (amphetamines, cocaine) had an increased risk of severe maternal morbidity (18-34 years: aOR: 1.92; 95 % CI: 1.80,2.0, >34 years: aOR: 1.85; 95 % CI: 1.66,2.06). Cannabis use disorders were not associated with an increased risk of severe maternal morbidity., Conclusion: Substance use disorders during pregnancy, particularly opioids, amphetamines, and cocaine use disorders, may contribute to severe maternal morbidity in the United States., (Copyright © 2020. Published by Elsevier B.V.)

Purpose: We determined the association between gestational weight gain and severe maternal morbidity., Methods: We used data on 84,241 delivery hospitalizations at Magee-Womens Hospital, Pittsburgh, PA (2003-2012). Total gestational weight gain (kilogram) was converted to gestational age-standardized z-scores. We defined severe maternal morbidity as having ≥1 of the 21 Centers for Disease Control diagnosis or procedure codes for severe maternal morbidity identification, intensive care unit admission, or extended postpartum stay. We used multivariable logistic regression to determine the association between weight gain and severe maternal morbidity after confounder adjustment., Results: High gestational weight gain z-scores were associated with an increased risk of severe maternal morbidity. Compared with z-score 0 SD (equivalent to 16 kg at 40 weeks in a normal-weight woman), risk differences (95% confidence intervals) for z-scores -2 SD (7 kg), -1 SD (11 kg), +1 SD (23 kg), and +2 SD (31 kg) were 1.5 (-0.71, 3.7), 0.056 (-0.81, 0.93), 3.4 (1.7, 5.0), and 8.6 (4.0, 13) per 1000 deliveries. The results did not vary by gestational age at delivery or prepregnancy body mass index., Conclusions: The increased risk of severe maternal morbidity with high pregnancy weight gain may allow scientists to understand and prevent this serious condition., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Conventional analytic approaches for studying diet patterns assume no dietary synergy, which can lead to bias if incorrectly modeled. Machine learning algorithms can overcome these limitations., Objectives: We estimated associations between fruit and vegetable intake relative to total energy intake and adverse pregnancy outcomes using targeted maximum likelihood estimation (TMLE) paired with the ensemble machine learning algorithm Super Learner, and compared these with results generated from multivariable logistic regression., Methods: We used data from 7572 women in the Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be. Usual daily periconceptional intake of total fruits and total vegetables was estimated from an FFQ. We calculated the marginal risk of preterm birth, small-for-gestational-age (SGA) birth, gestational diabetes, and pre-eclampsia according to density of fruits and vegetables (cups/1000 kcal) ≥80th percentile compared with <80th percentile using multivariable logistic regression and Super Learner with TMLE. Models were adjusted for confounders, including other Healthy Eating Index-2010 components., Results: Using logistic regression, higher fruit and high vegetable densities were associated with 1.1% and 1.4% reductions in pre-eclampsia risk compared with lower densities, respectively. They were not associated with the 3 other outcomes. Using Super Learner with TMLE, high fruit and vegetable densities were associated with fewer cases of preterm birth (-4.0; 95% CI: -4.9, -3.0 and -3.7; 95% CI: -5.0, -2.3), SGA (-1.7; 95% CI: -2.9, -0.51 and -3.8; 95% CI: -5.0, -2.5), and pre-eclampsia (-3.2; 95% CI: -4.2, -2.2 and -4.0; 95% CI: -5.2, -2.7) per 100 births, respectively, and high vegetable densities were associated with a 0.9% increase in risk of gestational diabetes., Conclusions: The differences in results between Super Learner with TMLE and logistic regression suggest that dietary synergy, which is accounted for in machine learning, may play a role in pregnancy outcomes. This innovative methodology for analyzing dietary data has the potential to advance the study of diet patterns., (Copyright © The Author(s) on behalf of the American Society for Nutrition 2020.)

Purpose: Inversed probability weighted (IPW) estimators are commonly used to adjust for time-fixed or time-varying confounders. However, in high-dimensional settings, including all identified confounders may result in unstable weights leading to higher variance. We aimed to develop a visualization tool demonstrating the impact of each confounder on the bias and variance of IPW estimates, as well as the propensity score overlap., Methods: A SAS macro was developed for this visualization tool and we demonstrate how this tool can be used to identify potentially problematic confounders of the association of statin use after myocardial infarction on one-year mortality in a plasmode simulation study using a cohort of 39,792 patients from the UK (1998-2012)., Results: Through the tool's output, we can identify problematic confounders (two instrumental variables) and important confounders by comparing the estimated psuedo MSE with that from the fully adjusted model and propensity score overlap plot., Conclusion: Our results suggest that the analytic impact of all confounders should be considered carefully when fitting IPW estimators., (Copyright © 2019. Published by Elsevier Inc.)

Objective: To investigate the association between early-pregnancy weight gain and risk of preeclampsia to inform pregnancy weight gain recommendations., Study Design: We performed a case-cohort study using a hospital database including 80,812 singleton deliveries from Magee-Womens Hospital, Pittsburgh, Pennsylvania (1998-2011). In each of 6 prepregnancy body mass index (BMI) groups, we abstracted serial antenatal weight measurements from the records of up to 339 preeclampsia cases and 1254 randomly selected pregnancies. Early gestational weight gain (16-19 weeks' gestation) was standardized for gestational duration using BMI-specific z-score charts. Multivariable log-binomial regression was used to assess the association between weight gain z-score and risk of preeclampsia. We determined the impact of preeclampsia misclassification using probabilistic bias analysis., Main Outcome Measure: Risk of preeclampsia., Results: For normal weight women, there was a steady increase in preeclampsia risk with increasing early gestational weight gain z-score. For example, compared with a weight gain of 1.2 kg (z-score = -1 SD), a 7.2-kg weight gain (z-score = +1 SD) at 16 weeks was associated with 1.3 (0.50, 2.2) excess preeclampsia cases per 100 deliveries. Weight loss at 16-19 weeks among grade 2 or 3 obese women was associated with a reduced risk of preeclampsia. Associations were null among overweight and grade 1 obese women. The bias analysis supported the validity of the conventional analysis., Conclusions: Early-pregnancy weight gain may be associated with preeclampsia in some BMI groups. Future revisions of pregnancy weight gain recommendations should account for preeclampsia risks from this and additional studies., (Copyright © 2018 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.)

Background: Objectives were to characterize how scientific information about prenatal and postpartum marijuana use was presented in online media content, and to assess how media portrayed risks and benefits of such marijuana use., Methods: We analyzed online media items (n = 316) from March 2015 to January 2017. A codebook was developed to measure media content in 4 domains: scientific studies, information about health and well-being, mode of ingestion, and portrayal of risks and benefits. Content analysis was performed by two authors, with high inter-rater reliability (mean ĸ = 0.82). Descriptive statistics were used to characterize content, and regression analyses were used to test for predictors of media portrayal of the risk-benefit ratio of prenatal and postpartum marijuana use., Results: 51% of the media items mentioned health risks of prenatal and postpartum marijuana use. Nearly one-third (28%) mentioned marijuana use for treatment of nausea and vomiting in pregnancy. Most media items mentioned a specific research study. More than half of media (59%) portrayed prenatal or postpartum marijuana risks > benefits, 10% portrayed benefits> risks, and the remainder were neutral. While mention of a scientific study was not predictive of the portrayal of the risk-benefit ratio of marijuana use in pregnancy or postpartum, discussion of health risks and health benefits predicted portrayals of the risk-benefit ratio., Conclusions: Online media content about prenatal and postpartum marijuana use presented health risks consistent with evidence, and discussed a health benefit of marijuana use for nausea and vomiting in pregnancy. Portrayal of risks and benefits was somewhat equivocal, consistent with current scientific debate., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Gestational diabetes mellitus (GDM) affects approximately 5 to 7% of pregnancies and is associated with increased risk for fetal overgrowth, cesarean delivery, birth trauma, and pre-eclampsia. GDM is commonly diagnosed in the US using a two-step screening and confirmatory approach, whereas a one-step approach is commonly used outside the US. Recent guidelines have suggested that the one-step approach should be used to diagnose GDM, although concern that this may increase the prevalence of GDM to approximately 18%-as well as the lack of clinical trials-based evidence regarding the difference in perinatal outcomes-has led to skepticism about adopting the one-step approach. The Comparison of Two Screening Strategies for Gestational Diabetes (GDM 2 ) Trial is a single-center, parallel-arm, comparative effectiveness trial of one-step versus two-step GDM screening strategies on the rate of adverse perinatal outcomes including: large-for-gestational age (LGA) deliveries (primary outcome), small-for-gestational age (SGA), macrosomia, cesarean delivery, fetal growth and body composition, and maternal and neonatal composite outcomes. This paper describes the design and analysis plan of the GDM 2 Trial as well as overall challenges in assessing the impact of screening and diagnosis strategy on adverse pregnancy outcomes. We will also assess whether the additional women diagnosed with the one-step approach benefit from treatment as assessed by metabolic profiles at one year postpartum. Ultimately, this study will provide the necessary evidence for establishing universal guidelines for GDM diagnosis and implementation into clinical care., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: The significance of periconceptional nutrition for optimizing offspring and maternal health and reducing social inequalities warrants greater understanding of diet quality among US women., Objective: Our objective was to evaluate racial or ethnic and education inequalities in periconceptional diet quality and sources of energy and micronutrients., Design: Cross-sectional analysis of data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be cohort., Participants and Setting: Nulliparous women (N=7,511) were enrolled across eight US medical centers from 2010 to 2013., Main Outcome Measures: A semiquantitative food frequency questionnaire assessing usual dietary intake during the 3 months around conception was self-administered during the first trimester. Diet quality, measured using the Healthy Eating Index-2010 (HEI-2010), and sources of energy and micronutrients were the outcomes., Statistical Analyses: Differences in diet quality were tested across maternal racial or ethnic and education groups using F tests associated with analysis of variance and χ 2 tests., Results: HEI-2010 score increased with higher education, but the increase among non-Hispanic black women was smaller than among non-Hispanic whites and Hispanics (interaction P value <0.0001). For all groups, average scores for HEI-2010 components were below recommendations. Top sources of energy were sugar-sweetened beverages, pasta dishes, and grain desserts, but sources varied by race or ethnicity and education. Approximately 34% of energy consumed was from empty calories (the sum of energy from added sugars, solid fats, and alcohol beyond moderate levels). The primary sources of iron, folate, and vitamin C were juices and enriched breads., Conclusions: Diet quality is suboptimal around conception, particularly among women who are non-Hispanic black, Hispanic, or who had less than a college degree. Diet quality could be improved by substituting intakes of refined grains and foods empty in calories with vegetables, peas and beans (legumes), seafood, and whole grains., (Copyright © 2017 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.)

Purpose: To quantify the relationship between pregnancy weight gain with early and late preterm birth and evaluate whether associations differed between non-Hispanic (NH) black and NH white women., Methods: We analyzed a retrospective cohort of all live births to NH black and NH white women in the United States 2011-2015 (n = 10,714,983). We used weight gain z-scores in multiple logistic regression models stratified by prepregnancy body mass index (BMI) and race to calculate population attributable risk (PAR) percentages for the contribution of high and low pregnancy weight gain to early and late preterm birth., Results: Pregnancy weight gain was related to early and late preterm birth, but associations varied by BMI and race. For early preterm birth, the PAR percentage for high pregnancy weight gain ranged from 8 to 10% in NH black women and from 6 to 8% in NH white women. There was little evidence of racial differences in late preterm birth: PAR percentages ranged from 2 to 7% in NH black women and from 3 to 7% in NH white women., Conclusions: Moderate gestational weight gain is associated with lower rate of preterm birth, with greatest reductions for early preterm birth in NH black women., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: The objective of this case-cohort study was to evaluate the relationship between maternal 25-hydroxyvitamin D (25(OH)D) concentration and preeclampsia overall and by severity., Methods: From an eligible cohort of 12,861 women who had serum banked from aneuploidy screening in Pittsburgh, Pennsylvania from 1999 to 2010, we randomly sampled a subcohort of 2327 pregnancies and all remaining preeclampsia cases (n = 650 cases). Preeclampsia (defined as new-onset hypertension and proteinuria) and its mild and severe forms were identified using ICD-9 codes. Maternal serum collected at 20 weeks or less gestation was measured for 25(OH)D. We used log-binomial regression with restricted cubic splines to estimate the association between 25(OH)D and preeclampsia after adjusting for confounders., Results: Approximately 21% of the randomly selected sample had 25(OH)D less than 50 nmol per L. We found that the adjusted risk of preeclampsia declined as serum 25(OH)D increased to 50 nmol per L and then plateaued (test of nonlinearity P < .05). The adjusted preeclampsia risk ratios (95% confidence intervals) for 25(OH)D less than 25 nmol per L, 25 to 49.9 nmol per L, and 50 to 74.9 nmol per L were 2.4 (1.2-4.8), 1.1 (0.69-1.7), and 1.3 (0.89-1.8), respectively, compared with those with 25(OH)D 75 nmol per L and over. Similar associations were observed with severe and mild preeclampsia., Conclusions: Vitamin D deficiency increases risks of severe and mild forms of preeclampsia., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Maternal overweight and obesity affect two-thirds of women of childbearing age and may increase the risk of impaired child cognition., Objective: Our objective was to test the hypothesis that high/low gestational weight gain (GWG) and high/low prepregnancy BMI were associated with offspring intelligence quotient (IQ) and executive function at age 10., Methods: Mother-infant dyads (n = 763) enrolled in a birth cohort study were followed from early pregnancy to 10 y postpartum. IQ was assessed by trained examiners with the use of the Stanford Binet Intelligence Scale-4th edition. Executive function was assessed by the number of perseverative errors on the Wisconsin Card Sorting Test and time to complete Part B on the Trail Making Test. Self-reported total GWG was converted to gestational-age-standardized GWG z score. Multivariable linear regression and negative binomial regression were used to estimate independent and joint effects of GWG and BMI on outcomes while adjusting for covariates., Results: At enrollment, the majority of women in the Maternal Health Practices and Child Development cohort were unmarried and unemployed, and more than one-half reported their race as black. The mean ± SD GWG z score was -0.5 ± 1.8, and 27% of women had a pregravid BMI ≥ 25. The median (IQR) number of perseverative errors was 23 (17, 29), the mean ± SD time on Part B was 103 ± 42.6 s, and 44% of children had a low average IQ (≤ 89). Maternal obesity was associated with 3.2 lower IQ points (95% CI: -5.6, -0.8) and a slower time to complete the executive function scale Part B (adjusted β: 12.7 s; 95% CI: 2.8, 23 s) compared with offspring of normal-weight mothers. Offspring of mothers whose GWG was >+1 SD, compared with -1 to +1 SD, performed 15 s slower on the executive function task (95% CI: 1.8, 28 s). There was no association between GWG z score and offspring composite IQ score (adjusted β: -0.32; 95% CI: -0.72, 0.10). Prepregnancy BMI did not modify these associations., Conclusions: Although GWG may be important for executive function, maternal BMI has a stronger relation than GWG to both offspring intelligence and executive function. Our findings contribute to evidence linking maternal obesity to long-term child outcomes., (© 2015 American Society for Nutrition.)

Background: In high-income countries, maternal obesity is one of the most important modifiable causes of stillbirth, yet the pathways underpinning this association remain unclear., Objective: We estimated the association between maternal prepregnancy body mass index (BMI) and the risk of stillbirth defined by pathophysiologic contributors or causes., Design: Using a case-cohort design, we randomly sampled 1829 singleton deliveries from a cohort of 68,437 eligible deliveries at Magee-Womens Hospital in Pittsburgh, Pennsylvania (2003-2010), and augmented it with all remaining cases of stillbirth for a total of 658 cases. Stillbirths were classified based on probable cause(s) of death (maternal medical conditions, obstetric complications, fetal abnormalities, placental diseases, and infection). A panel of clinical experts reviewed medical records, placental tissue slides and pathology reports, and fetal postmortem reports of all stillbirths. Causes of fetal death were assigned by using the Stillbirth Collaborative Research Network Initial Causes of Fetal Death protocol from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Proportional hazards models were used to estimate the BMI-stillbirth association after adjustment for confounders., Results: The rate of stillbirth among lean, overweight, obese, and severely obese women was 7.7, 10.6, 13.9, and 17.3 per 1000 live-born and stillborn infants, respectively. Adjusted stillbirth HRs (95% CIs) were 1.4 (1.1, 1.8) for overweight, 1.8 (1.3, 2.4) for obese, and 2.0 (1.5, 2.8) for severely obese women, respectively, compared with lean women; associations strengthened when limited to antepartum stillbirths. Obesity and severe obesity were associated with stillbirth resulting from placental diseases, hypertension, fetal anomalies, and umbilical cord abnormalities. BMI was not related to stillbirth caused by placental abruption, obstetric conditions, or infection., Conclusions: Multiple mechanisms appear to link obesity to stillbirth. Interventions to reduce stillbirth among obese mothers should consider targeting stillbirth due to hypertension and placental diseases-the most common causes of fetal death in this at-risk group., (© 2015 American Society for Nutrition.)

Background: Current approaches for establishing public health guidelines on the recommended range of weight gain in pregnancy are subjective and nonsystematic., Objective: In this article, we outline how decision-making on gestational weight-gain guidelines could be aided by quantitative approaches used in noninferiority trials., Design: We reviewed the theoretical application of noninferiority margins to pregnancy weight-gain guidelines. A worked example illustrated the selection of the recommended range of pregnancy weight gain in women who delivered at the Magee-Womens Hospital, Pittsburgh, PA, in 2003-2010 by identifying weight-gain z scores in which risk of unplanned cesarean delivery, preterm birth, small-for-gestational-age infant, and large-for-gestational-age infant were not meaningfully increased (based on noninferiority margins of 10% and 20%)., Results: In normal-weight women, lowest risk of adverse perinatal outcome was observed at a weight-gain z score of -0.2 SDs. With a noninferiority margin of 20%, risks of adverse outcome were not meaningfully increased from the -0.2-SD reference value between z scores of -0.97 and +0.33 SDs (which corresponded to 11.3-18.4 kg). In overweight women, the recommended range was much broader: -2.11 to +0.29 SDs (4.4-18.1 kg)., Conclusion: The new approach illustrated in this article has a number of advantages over current methods for establishing pregnancy weight-gain guidelines because it is systematic, it is reproducible, and it provides a tool for policy makers to derive guidelines that explicitly reflect values at which risk of adverse outcome becomes meaningfully increased., (© 2014 American Society for Nutrition.)

Background: Researchers have proposed biologically plausible mechanisms linking excessive gestational weight gain (GWG) to maternal metabolic and cardiovascular diseases later in life., Objective: The objective was to determine the extent to which GWG was associated with abdominal adiposity and other cardiometabolic risk factors in a sample of women 4-12 y after delivery., Design: We used data from The Women's and Infants' Study of Healthy Hearts, a cohort of women who gave birth between 1997 and 2002 at Magee-Womens Hospital in Pittsburgh, PA. By design, women with small-for-gestational-age and preterm births were oversampled. Women with preeclampsia, prepregnancy hypertension, or diabetes were excluded. GWG was ascertained from prenatal records, and GWG adequacy was assessed according to 2009 Institute of Medicine/National Research Council guidelines. Abdominal obesity was defined as waist circumference (WC) >88 cm and weight change as current weight - prepregnancy weight., Results: The prevalence of inadequate, adequate, and excessive GWG was 22% (107/478), 30% (145/478), and 47% (226/478), respectively. The analyses were adjusted for age at outcome assessment, prepregnancy BMI, marital status and insurance at delivery, race, smoking during target pregnancy, and current education, parity, and smoking. Associations between excessive GWG and blood pressure, lipids, glucose, insulin, and metabolic syndrome were null. However, women with excessive GWG had a 3.6-kg (1.5, 5.6) greater weight change, a 3.2-cm (1.2, 5.2) greater WC, and 3-fold greater odds of abdominal obesity (2.9; 1.6, 5.1) compared with women who gained weight as recommended., Conclusion: Excessive GWG is associated with long-term maternal abdominal adiposity, which may increase a woman's risk of cardiovascular and metabolic disease.

Background: Maternal vitamin D deficiency has been linked to fetal growth restriction, but the underlying mechanisms are unclear., Objective: We tested the hypothesis that poor maternal 25-hydroxyvitamin D [25(OH)D] is associated with increased risk of placental vascular pathology., Design: Maternal serum 25(OH)D was measured at ≤26 wk of gestation in a random subcohort of term, singleton infants in the Collaborative Perinatal Project (1959-1966; n = 2048). A dichotomous vascular construct was created from the presence of any of 12 pathologies identified on placental examinations, including evidence of placental abruption, infarction, hypoxia, decidual vasculopathy, or thrombosis of fetal vessels (n = 240 cases)., Results: The relation between 25(OH)D and vascular pathology was modified by infant sex (P = 0.003). A maternal 25(OH)D concentration ≥80 compared with <50 nmol/L was associated with 49% lower risk of pathology in boys [adjusted OR (95% CI): 0.27, 0.95] after conditioning on study site. No associations were observed between maternal 25(OH)D and pathology in mothers with female offspring. Subsequent analyses showed that, in pregnancies with a female fetus, vascular pathology was associated with a reduced birth-weight z score when the mother's 25(OH)D concentration was <30 nmol/L (β: -0.73; 95% CI: -1.17, -0.30). No association was observed between pathology and birth weight in mothers of female offspring with 25(OH)D concentrations ≥30 nmol/L or in boys, regardless of maternal 25(OH)D status., Conclusions: Our findings suggest complex relations between vitamin D, placental vascular pathology, and birth weight that differ by infant sex. Maternal vitamin D status may be beneficial for male and female offspring through different mechanisms.

Background: To establish the unbiased relation between maternal weight gain in pregnancy and perinatal health, a classification for maternal weight gain is needed that is uncorrelated with gestational age., Objective: The goal of this study was to create a weight-gain-for-gestational-age percentile and z score chart to describe the mean, SD, and selected percentiles of maternal weight gain throughout pregnancy in a contemporary cohort of US women., Design: The study population was drawn from normal-weight women with uncomplicated, singleton pregnancies who delivered at the Magee-Womens Hospital in Pittsburgh, PA, 1998-2008. Analyses were based on a randomly selected subset of 648 women for whom serial prenatal weight measurements were available through medical chart record abstraction (6727 weight measurements)., Results: The pattern of maternal weight gain throughout gestation was estimated by using a random-effects regression model. The estimates were used to create a chart with the smoothed means, percentiles, and SDs of gestational weight gain for each week of pregnancy., Conclusion: This chart allows researchers to express total weight gain as an age-standardized z score, which can be used in epidemiologic analyses to study the association between pregnancy weight gain and adverse or physiologic pregnancy outcomes independent of gestational age.

Background: The intake of periconceptional multivitamins may decrease the risk of preterm births (PTBs) or small-for-gestational-age (SGA) births., Objective: We related the timing and frequency of periconceptional multivitamin use to SGA births and PTBs and its clinical presentations (ie, preterm labor, premature rupture of membranes, and medical induction)., Design: Women in the Danish National Birth Cohort (n = 35,897) reported the number of weeks of multivitamin use during a 12-wk periconceptional period. Cox regression was used to estimate the relation between any multivitamin use and PTBs (<37 wk) or SGA births (birth weight adjusted for gestational age >2 SDs below the mean on the basis of fetal growth curves). The timing (preconception and postconception) and frequency of use were also analyzed. Regular users (4-6 wk) and partial users (1-3 wk) in each period were compared with nonusers., Results: The association between periconceptional multivitamin use and PTBs varied according to prepregnancy overweight status (P-interaction = 0.07). Regular preconception and postconception multivitamin use in women with a prepregnancy BMI (in kg/m(2)) <25 was associated with reduced risks of a PTB (HR: 0.84; 95% CI: 0.73, 0.95) and preterm labor (HR: 0.80; 95% CI: 0.69, 0.94). No similar associations were shown for overweight women. The adjusted risk of an SGA birth was reduced in multivitamin users regardless of their prepregnancy BMI (HR: 0.83; 95% CI: 0.73, 0.95), with the strongest association in regular users in the postconception period., Conclusion: Regular periconceptional multivitamin use was associated with reduced risk of SGA births and PTBs in nonoverweight women.

Objective: We previously reported that elevated antiinflammatory cervical cytokines in early pregnancy were associated with spontaneous preterm birth. Our objective was to explore the relation between serum folate vitamers and the lower genital tract inflammatory milieu., Study Design: Pregnant women (n = 417) at <16 weeks' gestation had serum samples that were analyzed for folate species 5-methyltetrahydrofolate, 5-formyltetrahydrofolate, and cervical fluid that was assayed for cytokine concentrations. Patterns in proinflammatory cytokines (interleukin [IL]-1β, -6, -8, and -10; monocyte chemotactic protein-1) and antiinflammatory cytokines (IL-4, IL-10, IL-13) were identified with factor analysis., Results: After confounder adjustment, maternal serum 5-methyltetrahydrofolate concentrations had a strong negative association with elevated antiinflammatory scores; serum 5-formyltetrahydrofolate concentrations were associated positively with elevated antiinflammatory scores (both P < .05). Maternal folate was not associated with proinflammatory scores., Conclusion: Maternal serum folate vitamers are associated with cervical cytokine concentrations, which suggests a possible mechanistic link between folate and preterm birth risk., (Copyright © 2011 Mosby, Inc. All rights reserved.)

The incidence of obesity is increasing at an alarming rate. There is compelling evidence that obesity increases the risk of preeclampsia about 3-fold, and in developed countries is the leading attributable risk for the disorder. In this presentation we explore this relationship and propose targets for future studies guided by the much more extensively studied relationship of obesity to cardiovascular disease. We further address the hypothesis that asymmetric dimethyl arginine (ADMA), an endogenous inhibitor of nitric oxide synthase, may be one convergence point for the mechanism by which obesity increases the risk of preeclampsia. We conclude with consideration of the clinical implications of this information.

Background: Poor maternal folate status has been associated with an increased risk of preterm birth. However, major gaps remain in our understanding of how individual folate species relate to preterm birth., Objective: Our objective was to assess the association between maternal folate status as measured by 5-methyltetrahydrofolate (5MeTHF), 5-formyltetrahydrofolate (5FoTHF), and folic acid concentrations, which are the 3 primary folate species in serum, and the risk of preterm birth and spontaneous preterm birth (sPTB)., Design: A cohort of 313 pregnant women who received care at resident antepartum clinics at Magee-Womens Hospital (Pittsburgh, PA) (2003-2007) was enrolled at <16 wk gestation. We analyzed nonfasting blood samples that were drawn from subjects at enrollment for the 3 folate species by using HPLC-tandem mass spectrometry., Results: Serum 5MeTHF and 5FoTHF concentrations comprised 65% and 33% of total folate concentrations, respectively. In confounder-adjusted, multivariable, log-binomial regression models, 1-SD increases in serum total folate and serum 5MeTHF concentrations were associated with significant reductions in the risk of sPTB (P < 0.05). There was a significant interaction between serum 5MeTHF and 5FoTHF concentrations and risk of preterm birth (P = 0.01). When serum 5MeTHF concentrations were low, there was a positive linear relation between 5FoTHF and risk of preterm birth. When 5MeTHF concentrations were high, there was a strong negative relation between 5FoTHF and preterm birth., Conclusions: Our results imply that the relative concentrations of folate species may be more critical than total folate in preventing preterm birth. An improved understanding of folate metabolism during pregnancy may lead to targeted intervention strategies that decrease the rate of preterm birth.

Background: The 2009 Institute of Medicine (IOM) Committee to Reevaluate Gestational Weight Gain Guidelines concluded that there were too few data to inform weight-gain guidelines by obesity severity. Therefore, the committee recommended a single range, 5-9 kg at term, for all obese women., Objective: We explored associations between gestational weight gain and small-for-gestational-age (SGA) births, large-for-gestational-age (LGA) births, spontaneous preterm births (sPTBs), and medically indicated preterm births (iPTBs) among obese women who were stratified by severity of obesity., Design: We studied a cohort of singleton, live-born infants without congenital anomalies born to obesity class 1 (prepregnancy body mass index [BMI (in kg/m(2))]: 30-34.9; n = 3254), class 2 (BMI: 35-39.9; n = 1451), and class 3 (BMI: > or =40; n = 845) mothers. We defined the adequacy of gestational weight gain as the ratio of observed weight gain to IOM-recommended gestational weight gain., Results: The prevalence of excessive gestational weight gain declined, and weight loss increased, as obesity became more severe. Generally, weight loss was associated with an elevated risk of SGA, iPTB, and sPTB, and a high weight gain tended to increase the risk of LGA and iPTB. Weight gains associated with probabilities of SGA and LGA of < or =10% and a minimal risk of iPTB and sPTB were as follows: 9.1-13.5 kg (obesity class 1), 5.0-9 kg (obesity class 2), 2.2 to <5.0 kg (obesity class 3 white women), and <2.2 kg (obesity class 3 black women)., Conclusion: These data suggest that the range of gestational weight gain to balance risks of SGA, LGA, sPTB, and iPTB may vary by severity of obesity.

Maternal vitamin D deficiency has been associated with numerous adverse health outcomes, but its association with fetal growth restriction remains uncertain. We sought to elucidate the association between maternal serum 25-hydroxyvitamin D [25(OH)D] concentrations in early pregnancy and the risk of small-for-gestational age birth (SGA) and explore the association between maternal single nucleotide polymorphisms (SNP) in the vitamin D receptor (VDR) gene and the risk of SGA. We conducted a nested case-control study of nulliparous pregnant women with singleton pregnancies who delivered SGA infants (n = 77 white and n = 34 black) or non-SGA infants (n = 196 white and n = 105 black). Women were followed from <16 wk gestation to delivery. Women's banked sera at <22 wk were newly measured for 25(OH)D and DNA extracted for VDR genotyping. SGA was defined as live-born infants that were <10th percentile of birth weight according to nomograms based on gender and gestational age. After confounder adjustment, there was a U-shaped relation between serum 25(OH)D and risk of SGA among white mothers, with the lowest risk from 60 to 80 nmol/L. Compared with serum 25(OH)D 37.5-75 nmol/L, SGA odds ratios (95% CI) for levels <37.5 and >75 nmol/L were 7.5 (1.8, 31.9) and 2.1 (1.2, 3.8), respectively. There was no relation between 25(OH)D and SGA risk among black mothers. One SNP in the VDR gene among white women and 3 SNP in black women were significantly associated with SGA. Our results suggest that vitamin D has a complex relation with fetal growth that may vary by race.

Bacterial vaginosis (BV) is a highly prevalent vaginal infection that is associated with adverse pregnancy outcomes. Vitamin D exerts an influence on the immune system and may play a role in BV. The objective of this study was to examine the association between maternal vitamin D status and the prevalence of BV in early pregnancy. Women (n = 469) enrolled in a pregnancy cohort study at <16 wk underwent a pelvic examination and provided a blood sample for determination of serum 25-hydroxyvitamin D [25(OH)D]. BV was diagnosed using Gram-stained vaginal smears interpreted using the method of Nugent. Approximately 41% of women had BV (Nugent score 7-10) and 52% had a serum 25(OH)D concentration <37.5 nmol/L. The mean unadjusted serum 25(OH)D concentration was lower among BV cases (29.5 nmol/L; 95% CI: 27.1, 32.0) compared with women with normal vaginal flora (40.1 nmol/L; 95% CI: 37.0, 43.5; P < 0.001). BV prevalence decreased as vitamin D status improved (P < 0.001). Approximately 57% of the women with a serum 25(OH)D concentration <20 nmol/L had BV compared with 23% of women with a serum 25(OH)D concentration >80 nmol/L. There was a dose-response association between 25(OH)D and the prevalence of BV. The prevalence declined as 25(OH)D increased to 80 nmol/L, then reached a plateau. Compared with a serum 25(OH)D concentration of 75 nmol/L, there were 1.65-fold (95% CI: 1.01, 2.69) and 1.26-fold (1.01, 1.57) increases in the prevalence of BV associated with a serum 25(OH)D concentration of 20 and 50 nmol/L, respectively, after adjustment for race and sexually transmitted diseases. Vitamin D deficiency is associated with BV and may contribute to the strong racial disparity in the prevalence of BV.

In the past decade, research on the relation between vitamin D exposure and disease in population-based studies has increased exponentially. These studies have involved measurement of vitamin D exposure by means of several methods: blood assays, self-reported dietary and supplemental intakes, and sunlight exposure questionnaires or diaries. As with all exposure measurements, researchers must consider the validity of their assessment tools for capturing vitamin D exposure. The purpose of this article is to summarize our current understanding of the various approaches to measuring vitamin D status within populations as reviewed at the 2007 Experimental Biology symposium, "Assessment of Vitamin D in Population-Based Studies." In summary, serum 25-hydroxyvitamin D is the accepted biomarker for short-term vitamin D status, but estimates of long-term dietary and supplemental intakes of vitamin D and long-term sunlight exposure may be the most logistically feasible indicators of lifetime vitamin D exposure in population-based studies. Also discussed are issues investigators should consider when analyzing relations between vitamin D exposure and disease outcomes in population-based studies as well as research avenues that need further exploration. The best method for assessing vitamin D status in population-based studies will depend primarily on the research question asked and the critical window of vitamin D exposure hypothesized to be most important.

Objective: The purpose of this study was to determine the joint effects of maternal and paternal race on risk of bacterial vaginosis (BV) during the first trimester., Study Design: In this cohort of black women and white women with singleton gestation at <13 weeks (n = 325), BV was diagnosed by vaginal pH and Gram stain., Results: BV was less common among white women than black women. Paternal race modified the effect of maternal race on BV risk. BV risk was 2-fold greater among both white female-black male partners and black female-white male partners. BV risk was also 2-fold greater among black female-black male partners. Black race among both partners confers no additional risk than with 1 black partner., Conclusion: Paternal black race is an independent risk factor for BV during pregnancy and is as important a risk factor as maternal race. Studies of BV and adverse pregnancy outcomes should consider paternal race.

Objective: Women who deliver preterm infants may be at increased risk for cardiovascular disease, perhaps related to dyslipidemia., Study Design: In a nested case control study of women with spontaneous preterm birth, cholesterol, high-density lipoprotein, low-density lipoprotein, and triglycerides were evaluated. Lipid concentrations and gestational changes, as well as risk for preterm birth, were evaluated in women who delivered <34 (n = 23), >or=34-<37 (n = 67), and >or=37 weeks (n = 199)., Results: High cholesterol or triglycerides or=34-<37 weeks, respectively. Overweight women who delivered <34 weeks had particularly elevated early pregnancy concentrations of cholesterol and low-density lipoprotein; lean women with moderate preterm birth had elevated triglycerides. There was a reduced triglyceride response in the first half of pregnancy among women who delivered <34 weeks., Conclusion: Our results indicate the presence of dyslipidemia in women with spontaneous preterm birth.

Obesity is a risk factor for vitamin D deficiency, but this relation has not been studied among pregnant women, who must sustain their own vitamin D stores as well as those of their fetuses. Our objective was to assess the effect of prepregnancy BMI on maternal and newborn 25-hydroxyvitamin D [25(OH)D] concentrations. Serum 25(OH)D was measured at 4-21 wk gestation and predelivery in 200 white and 200 black pregnant women and in their neonates' cord blood. We used multivariable logistic regression models to assess the independent association between BMI and the odds of vitamin D deficiency [25(OH)D <50 nmol/L] after adjustment for race/ethnicity, season, gestational age, multivitamin use, physical activity, and maternal age. Compared with lean women (BMI <25), pregravid obese women (BMI >or=30) had lower adjusted mean serum 25(OH)D concentrations at 4-22 wk (56.5 vs. 62.7 nmol/L; P < 0.05) and a higher prevalence vitamin D deficiency (61 vs. 36%; P < 0.01). Vitamin D status of neonates born to obese mothers was poorer than neonates of lean mothers (adjusted mean, 50.1 vs. 56.3 nmol/L; P < 0.05). There was a dose-response trend between prepregnancy BMI and vitamin D deficiency. An increase in BMI from 22 to 34 was associated with 2-fold (95% CI: 1.2, 3.6) and 2.1-fold (1.2, 3.8) increases in the odds of mid-pregnancy and neonatal vitamin D deficiency, respectively. The rise in maternal obesity highlights that maternal and newborn vitamin D deficiency will continue to be a serious public health problem until steps are taken to identify and treat low 25(OH)D.

Objective: The purpose of this study was to assess monthly patterns in preeclampsia risk separately by race/ethnicity., Study Design: We conducted a cohort study of 20,794 white women and 18,916 black women who received care at 12 hospitals in the United States., Results: Among white women, there was a significant U-shaped trend in the incidence of preeclampsia: the incidence was highest in winter months, reached its nadir in mid August, and subsequently increased through the fall months (P < .05). When compared with occurrences in January, the adjusted odds ratios were 0.65 (0.43, 0.99) for May, 0.76 (95% CI, 0.51, 1.13) for June, 0.64 (95% CI, 0.43, 0.97) for July, and 0.64 (95% CI, 0.42, 0.96) for August. Among black women, there was no association between month of delivery and preeclampsia risk (P = .81)., Conclusion: Our finding that the incidence of preeclampsia decreases in white women during the summer months and that no pattern exists in black women suggests that, in each subgroup, different or competing environmental exposures may be important for the pathogenesis of preeclampsia.

In utero or early-life vitamin D deficiency is associated with skeletal problems, type 1 diabetes, and schizophrenia, but the prevalence of vitamin D deficiency in U.S. pregnant women is unexplored. We sought to assess vitamin D status of pregnant women and their neonates residing in Pittsburgh by race and season. Serum 25-hydroxyvitamin D (25(OH)D) was measured at 4-21 wk gestation and predelivery in 200 white and 200 black pregnant women and in cord blood of their neonates. Over 90% of women used prenatal vitamins. Women and neonates were classified as vitamin D deficient [25(OH)D<37.5 nmol/L], insufficient [25(OH)D 37.5-80 nmol/L], or sufficient [25(OH)D>80 nmol/L]. At delivery, vitamin D deficiency and insufficiency occurred in 29.2% and 54.1% of black women and 45.6% and 46.8% black neonates, respectively. Five percent and 42.1% of white women and 9.7% and 56.4% of white neonates were vitamin D deficient and insufficient, respectively. Results were similar at <22 wk gestation. After adjustment for prepregnancy BMI and periconceptional multivitamin use, black women had a smaller mean increase in maternal 25(OH)D compared with white women from winter to summer (16.0+/-3.3 nmol/L vs. 23.2+/-3.7 nmol/L) and from spring to summer (13.2+/-3.0 nmol/L vs. 27.6+/-4.7 nmol/L) (P<0.01). These results suggest that black and white pregnant women and neonates residing in the northern US are at high risk of vitamin D insufficiency, even when mothers are compliant with prenatal vitamins. Higher-dose supplementation is needed to improve maternal and neonatal vitamin D nutriture.

Objective: We investigated changes in serum uric acid across pregnancy in women with gestational hyperuricemia at delivery, with and without preeclampsia, compared with normal pregnant and women with preeclampsia without gestational hyperuricemia., Study Design: This was a nested case-control study of 116 controls, 27 women with preeclampsia with predelivery hyperuricemia, 37 women with preeclampsia without predelivery hyperuricemia, and 35 women with gestational hypertension with hyperuricemia at delivery but without proteinuria. Serum uric acid and creatinine was measured across pregnancy., Results: Women with predelivery hyperuricemia, with and without preeclampsia, had increased uric acid concentrations across pregnancy compared with controls, after 25 weeks' gestation compared with women with preeclampsia without predelivery hyperuricemia. Adjusting for differences in glomerular filtration by serum creatinine accounted for part but not all of the increase in serum uric acid among women with preeclampsia and predelivery hyperuricemia., Conclusions: Among women with hyperuricemia at delivery, elevations in uric acid occur early. Multiple mechanisms may contribute to increased uric acid including changes in renal function.

Adequate nutrition is needed for countless aspects of brain functioning. Poor diet quality, ubiquitous in the United States, may be a modifiable risk factor for depression. The objective was to review and synthesize the current knowledge of the role of nutrition in depression, and address implications for childbearing-aged women. Poor omega-3 fatty acid status increases the risk of depression. Fish oil and folic acid supplements each have been used to treat depression successfully. Folate deficiency reduces the response to antidepressants. Deficiencies of folate, vitamin B12, iron, zinc, and selenium tend to be more common among depressed than nondepressed persons. Dietary antioxidants have not been studied rigorously in relation to depression. Childbearing-aged women are particularly vulnerable to the adverse effects of poor nutrition on mood because pregnancy and lactation are major nutritional stressors to the body. The depletion of nutrient reserves throughout pregnancy and a lack of recovery postpartum may increase a woman's risk of depression. Prospective research studies are needed to clarify the role of nutrition in the pathophysiology of depression among childbearing-aged women. Greater attention to nutritional factors in mental health is warranted given that nutrition interventions can be inexpensive, safe, easy to administer, and generally acceptable to patients.

Purpose: To explore the dose-dependent relation between prepregnancy body mass index (BMI) and the risk of preeclampsia after adjusting for measured confounders., Methods: We studied 1179 primiparous women who enrolled at < 16 weeks' gestation into a prospective cohort study of the pathogenesis of preeclampsia. Multivariable logistic regression was used to quantify the independent effect of prepregnancy BMI on the risk of preeclampsia after adjusting for race and smoking status. BMI was specified as a restricted quadratic spline., Results: Preeclampsia risk rose strikingly from a BMI of 15 to 30 kg/m(2). Compared with women with a BMI of 21, the adjusted risk of preeclampsia doubled at a BMI of 26 (odds ratio 2.1 [95% confidence interval, 1.4, 3.4]), and nearly tripled at a BMI of 30 (2.9 [1.6, 5.3]). Women with a BMI of 17 had a 57% reduction in preeclampsia risk compared with women with a BMI of 21 (0.43 [0.25, 0.76]), and a BMI of 19 was associated with a 33% reduction in risk (0.66 [0.50, 0.87])., Conclusions: These results indicate that preeclampsia risk rises through most of the BMI distribution. The dramatic elevation in overweight prevalence in the United States may increase preeclampsia incidence in the future.

The postpartum period is conventionally thought to be the time of lowest iron deficiency risk because iron status is expected to improve dramatically after delivery. Nonetheless, recent studies have reported a high prevalence of postpartum iron deficiency and anemia among ethnically diverse low-income populations in the United States. In light of the recent emergence of this problem in the medical literature, we discuss updated findings on postpartum iron deficiency, including its prevalence, functional consequences, risk factors, and recommended primary and secondary prevention strategies. The productivity and cognitive gains made possible by improving iron nutriture support intervention. We therefore conclude that postpartum iron deficiency warrants greater attention and higher quality care.

Preeclampsia is a pregnancy-specific condition that increases maternal and infant mortality and morbidity. It is diagnosed by new-onset increased blood pressure and proteinuria during gestation; for many years these markers were the sole targets for study. More recently, increased attention to the multisystemic nature of the syndrome with involvement of almost all organs, activation of coagulation and increased sensitivity to pressor agents has expanded understanding of the disorder. The epidemiology of preeclampsia, being more common in poor women, long ago suggested that nutrients might be involved in the disorder. Numerous conflicting hypotheses were advanced but the testing of these hypotheses has either been done poorly or not at all. Review of the available data indicates very few studies that provide useful insights. In many studies the syndrome is poorly defined and in most studies nutritional data (questionnaires or biomarkers) are obtained on women with the clinical syndrome. In overtly preeclamptic women it is impossible to decipher cause from effect. Nonetheless, current concepts of the genesis of preeclampsia that include endothelial dysfunction, inflammatory activation, oxidative stress and predisposing maternal factors provide targets for well-designed nutritional investigation. In this review the current concepts of the pathogenesis of preeclampsia are reviewed and available data are assessed in light of these concepts. Targets for nutritional investigation based on the current knowledge of pathophysiology are suggested.

We estimated the prevalence of postpartum iron deficiency, anemia and iron deficiency anemia in the United States and compared risk of iron deficiency between women 0-24 mo postpartum (n = 680) and never-pregnant women, 20-40 y old (n = 587). We used data from National Health and Nutrition Examination Survey, 1988-1994. Iron deficiency was defined as abnormal values for > or = 2 of 3 iron status measures (serum ferritin, free erythrocyte protoporphyrin, transferrin saturation). Iron deficiency prevalences for women 0-6, 7-12 and 13-24 mo postpartum were 12.7, 12.4 and 7.8%, respectively, and 6.5% among never-pregnant women. After adjustment for confounding, the risk of iron deficiency among women with a poverty index ratio < or = 130% who were 0-6, 7-12 and 13-24 mo postpartum was 4.1 (95% confidence interval 2.0, 7.2), 3.1 (1.3, 6.5) and 2.0 (0.8, 4.1) times as great, respectively, as never-pregnant women with a poverty index ratio > 130%, but risk was not elevated for never-pregnant women with a poverty index ratio < or = 130%. Compared with the same referent, the risk of iron deficiency was not meaningfully different for women with a poverty index ratio > 130% who were 0-6, 7-12 or 13-24 mo postpartum. Given that low income postpartum women bear a substantially greater iron deficiency risk than never-pregnant women, more attention should be given to preventing iron deficiency among low income women during and after pregnancy.

Objective: The purpose of this study was to identify foods that contributed most to nutrient and fiber intake in a sample of pregnant women in North Carolina., Study Design: This was a prospective study of women in the Pregnancy, Infection, and Nutrition Study (n = 2247 women). Dietary information during the second trimester was collected with the use of a food frequency questionnaire. The contribution of each food item to the population's intake was calculated., Results: Overall, low nutrient-dense foods were major contributors to energy, fat, and carbohydrates, whereas fortified foods were important sources of iron, folate, and vitamin C. The median energy intake for this population was 2478 kcal. The median dietary intakes of iron were below the recommended levels. Although black women consumed more calories on average, white women, after energy adjustment, consumed greater amounts of protein, iron, folate, and fiber., Conclusion: These data emphasize the importance of evaluating both the nutrient density in the diet and the frequency of consumption in the assessment of the diets of pregnant women.