Association of Maternal Obesity With Longitudinal Ultrasonographic Measures of Fetal Growth: Findings From the NICHD Fetal Growth Studies-Singletons

The NICHD Fetal 3D Study: A Pregnancy Cohort Study of Fetal Body Composition and Volumes

There's a paucity of robust normal fractional limb and organ volume standards from a large and diverse ethnic population. The Fetal 3D Study was designed to develop research and clinical applications for fetal soft tissue and organ volume assessment. The NICHD Fetal Growth Studies (2009-2013) collected 2D and 3D fetal volumes. In the Fetal 3D Study (2015-2019), sonographers performed longitudinal 2D and 3D measurements for specific fetal anatomical structures in research ultrasounds of singletons and dichorionic twins. The primary aim was to establish standards for fetal body composition and organ volumes, overall and by maternal race/ethnicity, and determine whether these standards vary for twins versus singletons. We describe the study design, methods, and details about reviewer training. Basic characteristics of this cohort, with their corresponding distributions of fetal 3D measurements by anatomical structure, are summarized. This investigation is responsive to critical data gaps in understanding serial changes in fetal subcutaneous fat, lean body mass, and organ volume in association with pregnancy complications. In the future, this cohort can answer critical questions regarding the potential influence of maternal characteristics, lifestyle factors, nutrition, and biomarker and chemical data on longitudinal measures of fetal subcutaneous fat, lean body mass, and organ volumes.

Maternal obesity and placental function: impaired maternal-fetal axis

The prevalence of maternal obesity rapidly increases, which represents a major public health concern worldwide. Maternal obesity is characteristic by metabolic dysfunction and chronic inflammation. It is associated with health problems in both mother and offspring. Increasing evidence indicates that the placenta is an axis connecting maternal obesity with poor outcomes in the offspring. In this brief review, we have summarized the current data regarding deregulated placental function in maternal obesity. The data show that maternal obesity induces numerous placental defects, including lipid and glucose metabolism, stress response, inflammation, immune regulation and epigenetics. These placental defects affect each other and result in a stressful intrauterine environment, which transduces and mediates the adverse effects of maternal obesity to the fetus. Further investigations are required to explore the exact molecular alterations in the placenta in maternal obesity, which may pave the way to develop specific interventions for preventing epigenetic and metabolic programming in the fetus.

Fetal growth assessed via ultrasound in relation to maternal HIV infection status and antiretroviral regimens

OBJECTIVE

To evaluate effects of maternal HIV and antiretroviral treatment (ART) on intrauterine fetal growth.

DESIGN

Prospective cohort studies of HIV and ZIKA infection among women living with HIV (WLHIV) and women not living with HIV (WNLHIV) conducted in Brazil and the US from 2016 to 2020.

METHODS

We evaluated fetal growth via repeated ultrasounds and calculated z scores for fetal growth measures using Intergrowth-21st standards among women with singleton pregnancies. Adjusted linear mixed models were fit for each fetal growth z score by HIV status. Among WLHIV, we compared fetal growth z scores by the most common maternal ART regimens, stratified by timing of ART initiation.

RESULTS

We included 166 WLHIV and 705 WNLHIV; none had Zika infection. The z scores were similar for WLHIV and WNLHIV for femur length (latest third trimester median = 1.08) and estimated fetal weight (median ≈0.60); adjusted mean differences in fetal weight z scores by HIV status were less than 0.1 throughout gestation. Other fetal growth measurements were lower for WLHIV than WNLHIV early in gestation but increased more rapidly over gestation. Among WLHIV not on ART at conception, adjusted mean z scores were generally similar across regimens initiated during pregnancy but somewhat lower for atazanavir-based regimens for biparietal diameter compared with efavirenz-based or raltegravir-based regimens. Among WLHIV on ART at conception, mean z scores were similar across ART regimens.

CONCLUSION

Within our cohorts, fetal growth was lower in WLHIV than WNLHIV early in gestation but similar by the end of gestation, which is reassuring. Among WLHIV, fetal growth measures were generally similar across ART regimens evaluated.

Placental inflammation, oxidative stress, and fetal outcomes in maternal obesity

The obesity epidemic has led to a growing body of research investigating the consequences of maternal obesity on pregnancy and offspring health. The placenta, traditionally viewed as a passive intermediary between mother and fetus, is known to play a critical role in modulating the intrauterine environment and fetal development, and we now know that maternal obesity leads to increased inflammation, oxidative stress, and altered placental function. Here, we review recent research exploring the involvement of inflammation and oxidative stress as mechanisms impacting the placenta and fetus during obese pregnancy. Understanding them is crucial for informing strategies that can mitigate the adverse health effects of maternal obesity on offspring development and disease risk.

Racial and ethnic disparities in preterm birth: a mediation analysis incorporating mixtures of polybrominated diphenyl ethers

Background

Racial and ethnic disparities persist in preterm birth (PTB) and gestational age (GA) at delivery in the United States. It remains unclear whether exposure to environmental chemicals contributes to these disparities.

Objectives

We applied recent methodologies incorporating environmental mixtures as mediators in causal mediation analysis to examine whether racial and ethnic disparities in GA at delivery and PTB may be partially explained by exposures to polybrominated diphenyl ethers (PBDEs), a class of chemicals used as flame retardants in the United States.

Methods

Data from a multiracial/ethnic US cohort of 2008 individuals with low-risk singleton pregnancies were utilized, with plasma PBDE concentrations measured during early pregnancy. We performed mediation analyses incorporating three forms of mediators: (1) reducing all PBDEs to a weighted index, (2) selecting a PBDE congener, or (3) including all congeners simultaneously as multiple mediators, to evaluate whether PBDEs may contribute to the racial and ethnic disparities in PTB and GA at delivery, adjusted for potential confounders.

Results

Among the 2008 participants, 552 self-identified as non-Hispanic White, 504 self-identified as non-Hispanic Black, 568 self-identified as Hispanic, and 384 self-identified as Asian/Pacific Islander. The non-Hispanic Black individuals had the highest mean ∑PBDEs, the shortest mean GA at delivery, and the highest rate of PTB. Overall, the difference in GA at delivery comparing non-Hispanic Black to non-Hispanic White women was -0.30 (95% CI: -0.54, -0.05) weeks. This disparity reduced to -0.23 (95% CI: -0.49, 0.02) and -0.18 (95% CI: -0.46, 0.10) weeks if fixing everyone's weighted index of PBDEs to the median and the 25th percentile levels, respectively. The proportion of disparity mediated by the weighted index of PBDEs was 11.8%. No statistically significant mediation was found for PTB, other forms of mediator(s), or other racial and ethnic groups.

Conclusion

PBDE mixtures may partially mediate the Black vs. White disparity in GA at delivery. While further validations are needed, lowering the PBDEs at the population level might help reduce this disparity.

Association of fetal ultrasound anthropometric parameters with neurodevelopmental outcomes at 24 months of age

BACKGROUND

There is a paucity of studies which have examined associations between ultrasound based fetal anthropometric parameters and neurodevelopment in all infants. We examined the association between ultrasound based fetal anthropometric parameters and neurodevelopment in all infants through a secondary analysis of data collected in a large community based randomized controlled trial.

METHODS

A total of 1465 mother-child dyads were included. Ultrasound based fetal anthropometric parameters which included the head circumference (HC), abdominal circumference (AC), femur length (FL), biparietal diameter (BPD) and transcerebellar diameter (TCD) were collected at 26-28 weeks of gestation and their association with neurodevelopment at 24 months of age was examined.

RESULTS

Only the transcerebellar diameter z score was positively associated +0.54 units (95% CI: 0.15, 0.93) with motor composite score. When the neurodevelopment outcomes were analyzed as categorical, none of the fetal variables were associated with risk of moderate to severe neurodevelopment impairment.

CONCLUSION

The findings suggest that transcerebellar diameter could be useful for early prediction of neurodevelopmental outcomes in childhood.

CLINICAL TRIAL REGISTRATION

Clinical trial registration of Women and Infants Integrated Interventions for Growth Study Clinical Trial Registry-India, #CTRI/2017/06/008908; Registered on: 23/06/2017, (http://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=19339&EncHid=&userName=society%20for%20applied%20studies).

The relationship between obesity-related H19DMR methylation and H19 and IGF2 gene expression on offspring growth and body composition

Background and objective

Imprinted genes are important for the offspring development. To assess the relationship between obesity-related H19DMR methylation and H19 and IGF2 gene expression and offspring growth and body composition.

Methods

Thirty-nine overweight/obese and 25 normal weight pregnant women were selected from the "Araraquara Cohort Study" according to their pre-pregnancy BMI. Fetal growth and body composition and newborn growth were assessed, respectively, by ultrasound and anthropometry. The methylation of H19DMR in maternal blood, cord blood, maternal decidua and placental villi tissues was evaluated by methylation-sensitive restriction endonuclease qPCR, and H19 and IGF2 expression by relative real-time PCR quantification. Multiple linear regression models explored the associations of DNA methylation and gene expression with maternal, fetal, and newborn parameters.

Results

H19DMR was less methylated in maternal blood of the overweight/obese group. There were associations of H19DMR methylation in cord blood with centiles of fetal biparietal diameter (BPD) and abdominal subcutaneous fat thickness and newborn head circumference (HC); H19DMR methylation in maternal decidua with fetal occipitofrontal diameter (OFD), HC, and length; H19DMR methylation in placental villi with fetal OFD, HC and abdominal subcutaneous fat thickness and with newborn HC. H19 expression in maternal decidua was associated with fetal BPD and femur length centiles and in placental villi with fetal OFD and subcutaneous arm fat. IGF2 expression in maternal decidua was associated with fetal BPD and in placental villi with fetal OFD.

Conclusion

To our knowledge, this is the first study to demonstrate associations of imprinted genes variations at the maternal-fetal interface of the placenta and in cord blood with fetal body composition, supporting the involvement of epigenetic mechanisms in offspring growth and body composition.

Hormonal Determinants of Growth and Weight Gain in the Human Fetus and Preterm Infant

The factors controlling linear growth and weight gain in the human fetus and newborn infant are poorly understood. We review here the changes in linear growth, weight gain, lean body mass, and fat mass during mid- and late gestation and the early postnatal period in the context of changes in the secretion and action of maternal, placental, fetal, and neonatal hormones, growth factors, and adipocytokines. We assess the effects of hormonal determinants on placental nutrient delivery and the impact of preterm delivery on hormone expression and postnatal growth and metabolic function. We then discuss the effects of various maternal disorders and nutritional and pharmacologic interventions on fetal and perinatal hormone and growth factor production, growth, and fat deposition and consider important unresolved questions in the field.

Maternal Hemoglobin A1c in the Third-Trimester May Underestimate Maternal Hyperglycemia and Its Impact on Offspring in Perinatal Demise Associated With Gestational Diabetes Mellitus: An Autopsy Case Series

INTRODUCTION

Gestational diabetes mellitus (GDM) is a common metabolic disorder linked to adverse pregnancy outcomes. Recent research indicates that HbA1c is reliable in detecting maternal glycemia during the first trimester but may underestimate glucose intolerance in the late second to third trimesters. Therefore, it is reasonable to hypothesize that mothers with GDM, despite apparently normal HbA1c levels in the third trimester, may give birth to infants displaying characteristic features often seen in infants of diabetic mothers with suboptimal glycemic control. This study aimed to describe a case series of autopsy cases involving stillborn or deceased neonates delivered in the third trimester to mothers diagnosed with GDM and having normal HbA1c levels at or around the time of delivery. The primary focus was on identifying and documenting the characteristic features commonly associated with "infants of diabetic mothers" with suboptimal glycemic control in this series of cases.

MATERIALS AND METHODS

We conducted a retrospective review of autopsy reports from our institution spanning 7.5 years. The study included cases that met the following criteria: (1) stillborn or infants who died in the early neonatal period, delivered in the third trimester; (2) mothers diagnosed with GDM; (3) normal maternal HbA1c levels of ≤6.1% at or around the time of delivery; (4) birthweight or femoral length exceeding the 90th percentile for gestational age; and (5) absence of genetic aberrations. We also examined these cases for other characteristic features associated with "infants of diabetic mothers."

RESULTS

Ten autopsy cases met our inclusion criteria, including 9 stillbirths and 1 neonatal death. Gestational age at delivery ranged from 32 to 39 weeks (mean: 35.7 weeks). Femoral length exceeded the 90th percentile in all cases, and 6 cases had birthweights above the 90th percentile. Puffy facies were observed in 6 cases. Among the 9 cases with complete autopsies including internal examination, 6 exhibited excess adipose tissue, 4 had cardiomegaly, and 3 showed pancreatic islet hyperplasia. Hypoxic-ischemic encephalopathy was detected in 7 cases. No structural abnormalities were noted.

DISCUSSION

Our findings demonstrated that fetuses and neonates born to mothers with apparently normal HbA1c levels in the third trimester could still display characteristic features commonly observed in infants of diabetic mothers with poor glycemic control, also known as "infants of diabetic mothers." This study underscores the potential of third-trimester maternal HbA1c measurements to underestimate maternal glycemia and its consequential impact on fetal development, as well as the subsequent manifestation of features of "infants of diabetic mothers."

Early Pregnancy Maternal Plasma Phospholipid Saturated Fatty Acids and Fetal Growth: Findings from a Multi-Racial/Ethnic Birth Cohort in US

Saturated fatty acids (SFAs) during pregnancy are associated with disrupted metabolic programming among offspring at birth and later growth. We examined plasma phospholipid SFAs in early pregnancy and fetal growth throughout pregnancy. We enrolled 321 pregnant women from the NICHD Fetal Growth Studies-Singleton Cohort at gestational weeks 8-13. Ultrasonogram schedules were randomly assigned to capture weekly fetal growth. We measured plasma phospholipid SFAs at early pregnancy using blood samples and modeled fetal growth trajectories across tertiles of SFAs with cubic splines using linear mixed models after full adjustment. We then compared pairwise weekly fetal growth biometrics referencing the lowest tertile in each SFA using the Wald test. We found that even-chain and very long even-chain SFAs were inversely associated, whereas odd-chain SFAs were positively associated with fetal weight and size. Compared with the lowest tertile, the highest tertile of pentadecanoic acid (15:0) had a greater fetal weight and size, starting from week 13 until late pregnancy (at week 39: 3429.89 vs. 3269.08 g for estimated fetal weight; 328.14 vs. 323.00 mm for head circumference). Our findings could inspire future interventions using an alternative high-fat diet rich in odd-chain SFAs for optimal fetal growth.

Prenatal exposure to multiple environmental chemicals and birth size

BACKGROUND

Epidemiological studies addressing the combined effects of exposure to chemical mixtures at different stages of pregnancy on birth size are scarce.

OBJECTIVE

To evaluate the association between prenatal exposure to chemical mixtures and birth size.

METHODS

Our previous study repeatedly measured the urinary concentrations of 34 chemical substances among 743 pregnant women and identified three distinct clusters of exposed population and six dominant principal components of exposed chemicals in each trimester. In this study, we assessed the associations of these exposure profiles with birth weight, birth length, and ponderal index using multivariable linear regression.

RESULTS

We found that compared with women in cluster 1 (lower urinary chemical concentrations), women in cluster 2 (higher urinary concentrations of metals, benzothiazole, benzotriazole, and some phenols), and women in cluster 3 (higher urinary concentrations of phthalates) were more likely to give birth to children with higher birth length [0.23 cm (95% CI: -0.03, 0.49); 0.29 cm (95%CI: 0.03, 0.54), respectively]. This association was observed only in 1st trimester. In addition, prenatal exposure to PC3 (higher benzophenones loading) was associated with reduced birth length across pregnancy [-0.07 cm (95% CI: -0.18, 0.03) in 1st and 2nd trimester; -0.13 cm (95% CI: -0.24, -0.03) in 3rd trimester]. Exposure to PC6 (higher thallium and BPA loading in 2nd trimester) was associated with increased birth length [0.15 cm (95% CI: 0.05, 0.26)]. Compared with other outcomes, associations of both clusters and PCs with birth length were stronger, and these associations were more pronounced in boys.

IMPACT STATEMENT

Exposure to multiple chemicals simultaneously, the actual exposure situation of pregnant women, was associated with birth size, indicating that chemical mixtures should be taken more seriously when studying the health effects of pollutants.

Is the Biphasic Effect of Diabetes and Obesity on Fetal Growth a Risk Factor for Childhood Obesity?

In pregnancies of women with obesity or diabetes, neonates are often overgrown. Thus, the pregnancy period in these women offers a window of opportunity to reduce childhood obesity by preventing neonatal overgrowth. However, the focus has been almost exclusively on growth in late pregnancy. This perspective article addresses possible growth deviations earlier in pregnancy and their potential contribution to neonatal overgrowth. This narrative review focuses on six large-scale, longitudinal studies that included ∼14,400 pregnant women with at least three measurements of fetal growth. A biphasic pattern in growth deviation, including growth reduction in early pregnancy followed by overgrowth in late pregnancy, was found in fetuses of women with obesity, gestational diabetes mellitus (GDM), or type 1 diabetes compared with lean women and those with normal glucose tolerance. Fetuses of women with these conditions have reduced abdominal circumference (AC) and head circumference (HC) in early pregnancy (observed between 14 and 16 gestational weeks), while later in pregnancy they present the overgrown phenotype with larger AC and HC (from approximately 30 gestational weeks onwards). Fetuses with early-pregnancy growth reduction who end up overgrown presumably have undergone in utero catch-up growth. Similar to postnatal catch-up growth, this may confer a higher risk of obesity in later life. Potential long-term health consequences of early fetal growth reduction followed by in utero catch-up growth need to be explored.

A new method for customized fetal growth reference percentiles

BACKGROUND

Customized fetal growth charts assume birthweight at term to be normally distributed across the population with a constant coefficient of variation at earlier gestational ages. Thus, standard deviation used for computing percentiles (e.g., 10th, 90th) is assumed to be proportional to the customized mean, although this assumption has never been formally tested.

METHODS

In a secondary analysis of NICHD Fetal Growth Studies-Singletons (12 U.S. sites, 2009-2013) using longitudinal sonographic biometric data (n = 2288 pregnancies), we investigated the assumptions of normality and constant coefficient of variation by examining behavior of the mean and standard deviation, computed following the Gardosi method. We then created a more flexible model that customizes both mean and standard deviation using heteroscedastic regression and calculated customized percentiles directly using quantile regression, with an application in a separate study of 102, 012 deliveries, 37-41 weeks.

RESULTS

Analysis of term optimal birthweight challenged assumptions of proportionality and that values were normally distributed: at different mean birthweight values, standard deviation did not change linearly with mean birthweight and the percentile computed with the normality assumption deviated from empirical percentiles. Composite neonatal morbidity and mortality rates in relation to birthweight < 10th were higher for heteroscedastic and quantile models (10.3% and 10.0%, respectively) than the Gardosi model (7.2%), although prediction performance was similar among all three (c-statistic 0.52-0.53).

CONCLUSIONS

Our findings question normality and constant coefficient of variation assumptions of the Gardosi customization method. A heteroscedastic model captures unstable variance in customization characteristics which may improve detection of abnormal growth percentiles.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00912132.

Prenatal medication use in a prospective pregnancy cohort by pre-pregnancy obesity status

BACKGROUND

The association between obesity (body mass index (BMI) ≥ 30 kg/m2) and pattern of medication use during pregnancy in the United States is not well-studied. Higher pre-pregnancy BMI may be associated with increases or decreases in medication use across pregnancy as symptoms (e.g. reflux) or comorbidities (e.g. gestational diabetes) requiring treatment that may be associated with higher BMI could also change with advancing gestation.

OBJECTIVES

To determine whether prenatal medication use, by the number and types of medications, varies by pre-pregnancy obesity status.

METHODS

In a secondary data analysis of a racially/ethnically diverse prospective cohort of pregnant women with low risk for fetal abnormalities enrolled in the first trimester of pregnancy and followed to delivery (singleton, 12 United States clinical sites), free text medication data were obtained at enrollment and up to five follow-up visits and abstracted from medical records at delivery.

RESULTS

In 436 women with obesity and 1750 women without obesity (pre-pregnancy BMI, 19-29.9 kg/m2), more than 70% of pregnant women (77% of women with and 73% of women without obesity) reported taking at least one medication during pregnancy, respectively (adjusted risk ratio (aRR)=1.10, 95% confidence interval (CI)=1.01, 1.20), with 81% reporting two and 69% reporting three or more. A total of 17 classes of medications were identified. Among medication classes consumed by at least 5% of all women, the only class that differed between women with and without obesity was hormones and synthetic substitutes (including steroids, progesterone, diabetes, and thyroid medications) in which women with obesity took more medications (11 vs. 5%, aRR = 1.9, 95% CI = 1.38, 2.61) compared to women without obesity. Within this class, a higher percentage of women with obesity took diabetes medications (2.3 vs. 0.7%) and progesterone (3.4 vs. 1.3%) than their non-obese counterparts. Similar percentages of women with and without obesity reported consuming medications in the remaining medication classes including central nervous system agents (50 and 46%), gastrointestinal drugs (43 and 40%), anti-infective agents (23 and 21%), antihistamines (20 and 17%), autonomic drugs (10 and 9%), and respiratory tract agents (7 and 6%), respectively (p > 0.05 for all adjusted comparisons). There were no differences in medication use by obesity status across gestation. Since the study exclusion criteria limited the non-obese group to women without thyroid disease, in a sensitivity analysis we excluded all women who reported thyroid medication intake and still a higher proportion of women with obesity took the hormones and synthetic substitutes class compared to women without obesity.

CONCLUSION

Our findings suggest that pre-pregnancy obesity in otherwise healthy women is associated with a higher use of only selected medications (such as diabetes medications and progesterone) during pregnancy, while the intake of other more common medication types such as analgesics, antibiotics, and antacids does not vary by pre-pregnancy obesity status. As medication safety information for prenatal consumption is insufficient for many medications, these findings highlight the need for a more in-depth examination of factors associated with prenatal medication use.

Impact of prepregnancy body mass index on adverse pregnancy outcomes: analysis from the Longitudinal Indian Family hEalth cohort study

BACKGROUND

Both high and low maternal prepregnancy body mass index can lead to suboptimal fetal growth and risk of pregnancy complications. In developed countries, nearly half of all women of childbearing age are either overweight or obese, and most data linking maternal body mass index and adverse pregnancy complications are limited to these populations.

OBJECTIVE

This study aimed to prospectively evaluate the relationships between prepregnancy body mass index and adverse pregnancy outcomes using the Longitudinal Indian Family hEalth (LIFE) study.

STUDY DESIGN

We modeled the relationships between prepregnancy body mass index and adverse pregnancy outcomes such as low birthweight, preterm birth, cesarean delivery, intrauterine growth restriction, miscarriage, and fetal death among 675 women aged 15 to 35 years with singleton pregnancies in the Longitudinal Indian Family hEalth study, a population-based prospective pregnancy cohort study conducted in Telangana, India. Prepregnancy body mass index was calculated as weight in kilograms divided by height in meters squared and was classified into 4 categories using the World Health Organization recommendations for Asian adults. Prepregnancy body mass index was assessed at a mean of 12.3 months before pregnancy. Odds ratios and 95% confidence intervals of adverse pregnancy outcomes were modeled and adjusted for confounders.

RESULTS

Obese women had a 3-fold increased risk of cesarean delivery (odds ratio, 3.13; 95% confidence interval, 1.56-6.29) compared with normal-weight women. Those who were overweight also had a marginally increased risk of cesarean delivery, albeit not statistically significant (odds ratio, 1.17; 95% confidence interval, 0.61-2.24). Underweight women had a modestly increased risk of low birthweight, compared with normal-weight women (odds ratio, 1.12; 95% confidence interval, 0.71-1.77), although results were not significant. Conversely, obese (odds ratio, 0.71; 95% confidence interval, 0.28-1.77) and overweight (odds ratio, 0.61; 95% confidence interval, 0.24-1.51) women had a marginally decreased risk of low birthweight.

CONCLUSION

Our data suggest that women with elevated prepregnancy body mass index may have a higher risk of adverse pregnancy outcomes, especially cesarean delivery. Although this study has limited generalizability, our findings are generalizable to rural to periurban regions of India. Further studies exploring the translatability of these findings to other populations are needed. In addition, targeted prepregnancy intervention studies and programs that include counseling on optimization of preconception health and lifestyle modification for improvement of subsequent pregnancy outcomes among overweight and obese women are needed.

Pregnant Women Following Bariatric Surgery: a Focus on Maternal Mental Health and Its Impact on Birth Outcomes

PURPOSE

Bariatric surgery is associated with elevated risks for adverse birth outcomes, such as small-for-gestational-age infants (SGA). Maternal mental health is a critical regulator of fetal growth, but it is largely overlooked in pregnant women post-surgery. This study aimed to examine the associations between maternal mental health and birth outcomes in pregnant women post-bariatric surgery.

MATERIALS AND METHODS

This was a retrospective analysis of medical records of women who had a singleton delivery following Roux-en-Y gastric bypass or sleeve gastrectomy. Mental health measures included depression/anxiety and substance use (cigarettes, alcohol, opioids, and marijuana). Birth outcomes were fetal growth restriction, SGA, low birthweight, and preterm birth. Logistic regressions were used to assess the associations between maternal mental health and each of the birth outcomes. A post hoc logistic regression was conducted to assess factors that influenced maternal marijuana use.

RESULTS

Participants (N = 179) were mostly white (64.6%), non-Hispanic (84.5%), with a mean age of 32.7 ± 4.6 years, and mean body mass index of 37.2 ± 8.4 kg/m² at conception. Maternal marijuana use significantly increased the odds for fetal growth restriction, SGA, low birthweight, and preterm birth. Cigarette use increased the risk for low birthweight. Conversely, alcohol use was protective of low birthweight and preterm birth. A post hoc analysis revealed that married women were less likely to use marijuana than those who were single, divorced, or widowed.

CONCLUSION

This analysis identified marijuana and cigarette use as risk factors for adverse birth outcomes post-bariatric surgery. Future studies with larger sample sizes are needed to confirm study findings.

Plasma phospholipid polyunsaturated fatty acids composition in early pregnancy and fetal growth trajectories throughout pregnancy: Findings from the US fetal growth studies-singletons cohort

Background

We aimed to investigate plasma phospholipid PUFA levels in early pregnancy and fetal growth trajectories throughout pregnancy.

Methods

Within the NICHD Fetal Growth Studies–Singleton Cohort, we enrolled 2,802 pregnant women at gestational weeks 8–13 and randomly assigned them to four ultrasonogram schedules to capture weekly fetal growth throughout pregnancy. Eleven plasma phospholipid PUFAs were measured at early pregnancy using blood samples collected from a subsample of 321 pregnant women. We modeled fetal growth trajectories across tertiles of PUFAs with cubic splines using linear mixed models after adjusting for major confounders. We then compared pairwise weekly fetal growth biometrics referencing the lowest tertile in each PUFA using the Wald test.

Findings

Among plasma n-3 PUFAs in early pregnancy, docosahexaenoic acid (DHA, 22:6n3) and alpha-linolenic acid (ALA, 18:3n3) showed positive associations with all fetal growth measurements. For instance, compared with the lowest tertile, the highest tertile of DHA had greater estimated fetal growth (EFW) and abdominal circumference (AC), starting at 13 weeks of gestation and throughout pregnancy (at gestational week 38: 3235.3 vs. 3089.0 g for EFW; 344.6 vs. 339.2 mm for AC). As for plasma n-6 PUFAs, some showed positive associations (e.g., linoleic acid [LA], 18:2n6) while others (e.g., docosatetraenoic acid [DTA], 22:4n6) showed inverse associations with fetal growth measures.

Interpretation

Our data suggested that higher plasma levels of DHA and ALA in the first trimester were associated with increased fetal size and weight throughout subsequent pregnancy.

Funding

National Institute of Child Health and Human Development intramural funding.

The association between maternal pre-pregnancy BMI, gestational weight gain and child adiposity: A racial-ethnically diverse cohort of children

BACKGROUND

The prevalence of obesity in US children has more than tripled in the past 40 years; hence, it is critical to identify potentially modifiable factors that may mitigate the risk.

OBJECTIVES

To examine the association between maternal pre-pregnancy body mass index (BMI), gestational weight gain (GWG) and child adiposity as measured by BMI, waist circumference and percent body fat in a racial-ethnically diverse cohort.

METHODS

In a prospective cohort study of healthy women without chronic disease, we examined the association between pre-pregnancy BMI, GWG and child adiposity. Children ages 4-8 years (n = 816) in the Environmental Influences on Child Health Outcomes-NICHD Fetal Growth Studies were assessed. Trained study staff ascertained maternal pre-pregnancy BMI, GWG and child adiposity.

RESULTS

The odds of child obesity (≥95th BMI percentile) increased independently for each unit increase in maternal pre-pregnancy BMI [OR = 1.12 (95% CI: 1.08, 1.17)] and for each 5-kg increase in GWG [OR = 1.25 (95% CI: 1.07, 1.47)]. The odds of child waist circumference (≥85th percentile) also increased independently for pre-pregnancy BMI [OR = 1.09 (95% CI: 1.05, 1.12)] and GWG [OR = 1.18 (95% CI: 1.04, 1.34)].

CONCLUSIONS

Maternal pre-pregnancy BMI and GWG were each independently and positively associated with child obesity and high child waist circumference.

Recreational physical activity before and during pregnancy and placental DNA methylation-an epigenome-wide association study

BACKGROUND

Physical activity (PA) prior to and during pregnancy may have intergenerational effects on offspring health through placental epigenetic modifications. We are unaware of epidemiologic studies on longitudinal PA and placental DNA methylation.

OBJECTIVES

We evaluated the association between PA before and during pregnancy and placental DNA methylation.

METHODS

Placental tissues were obtained at delivery and methylation was measured using HumanMethylation450 Beadchips for participants in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies-Singletons among 298 participants. Using the Pregnancy Physical Activity Questionnaire, women recalled periconception PA (past 12 mo) at 8-13 wk of gestation and PA since last visit at 4 follow-up visits at 16-22, 24-29, 30-33, and 34-37 wk. We conducted linear regression for associations of PA at each visit with methylation controlling for false discovery rate (FDR). Top 100 CpGs were queried for enrichment of functional pathways using Ingenuity Pathway Analysis.

RESULTS

Periconception PA was significantly associated with 1 CpG site. PA since last visit for visits 1-4 was associated with 2, 2, 8, and 0 CpGs (log fold changes ranging from -0.0319 to 0.0080, after controlling for FDR). The largest change in methylation occurred at a site in TIMP2 , which is known to encode a protein critical for vasodilation, placentation, and uterine expansion during pregnancy (log fold change: -0.05; 95% CI: -0.06, -0.03 per metabolic equivalent of task-h/wk at 30-33 wk). Most significantly enriched pathways include cardiac hypertrophy signaling, B-cell receptor signaling, and netrin signaling. Significant CpGs and enriched pathways varied by visit.

CONCLUSIONS

Recreational PA in the year prior and during pregnancy was associated with placental DNA methylation. The associated CpG sites varied based on timing of PA. If replicated, the findings may inform the mechanisms underlying the impacts of PA on placenta health. This study was registered at clinicaltrials.gov as NCT00912132.

Associations of Obesity with Linear Growth and Puberty

BACKGROUND

The prevalence of obesity in childhood has increased dramatically in recent decades with increased risk of developing cardiometabolic and other comorbidities. Childhood adiposity may also influence processes of growth and puberty.

SUMMARY

Growth patterns of obesity during childhood have been shown to be associated with increased linear growth in early childhood, leading to accelerated epiphyseal growth plate (EGP) maturation. Several hormones secreted by the adipose tissue may affect linear growth in the context of obesity, both via the growth hormone IGF-1 axis and via a direct effect on the EGP. The observation that children with obesity tend to mature earlier than lean children has led to the assumption that the degree of body fatness may trigger the neuroendocrine events that lead to pubertal onset. The most probable link between obesity and puberty is leptin and its interaction with the kisspeptin system, which is an important regulator of puberty. However, peripheral action of adipose tissue could also be involved in changes in the onset of puberty. In addition, nutritional factors, epigenetics, and endocrine-disrupting chemicals are potential mediators linking pubertal onset to obesity. In this review, we focused on interactions of obesity with linear growth and pubertal processes, based on basic research and clinical data in humans.

KEY MESSAGE

Children with obesity are subject to accelerated linear growth with risk of impaired adult height and early puberty, with its psychological consequences. The data highlight another important objective in combatting childhood obesity, for the prevention of abnormal growth and pubertal patterns.

Sex-dependent influence of maternal predictors on fetal anthropometry in pregnancies with gestational diabetes mellitus

Background

Third trimester fetal anthropometric parameters are known to predict neonatal complications. A better understanding of predictors of adverse fetal parameters might help to personalize the use and frequency of fetal ultrasound. The objectives of this study were:

(a) to evaluate the utility of maternal sociodemographic, anthropometric and metabolic predictors to predict 3^rd trimester fetal anthropometric parameters in women with gestational diabetes mellitus (GDM),

(b) to assess whether the impact of these maternal predictors is fetal sex-dependent, and

(c) to provide a risk stratification for markers of fetal overgrowth (fetal weight centile (FWC) and fetal abdominal circumference centile (FACC) depending on prepregnancy BMI and gestational weight gain (GWG) until the 1^st GDM visit.

Methods

This prospective study included 189 women with GDM. Maternal predictors were age, ethnicity, prepregnancy BMI, GWG and excessive weight gain until the 1^st GDM visit, fasting, 1-hour and 2-hour blood glucose oral glucose tolerance test values, HbA1c at the 1^st visit and medical treatment requirement. Fetal outcomes included FWC, FWC >90% and <10%, FACC, FACC >90% and <10%, at 29 0/7 to 35 6/7 weeks of gestational age. We performed univariate and multivariate regression analyses and probability analyses.

Results

In multivariate analyses, prepregnancy BMI was associated with FWC, FWC > 90% and FACC. GWG until the 1^st GDM visit was associated with FWC, FACC and FACC > 90% (all p ≤ 0.045). Other maternal parameters were not significantly associated with fetal anthropometry in multivariate analyses (all p ≥ 0.054). In female fetuses, only GWG was associated with FACC (p= 0.044). However, in male fetuses, prepregnancy BMI was associated with FWC, FWC > 90% and FACC and GWG with FWC in multivariate analyses (all p ≤ 0.030). In women with a prepregnancy BMI of ≥ 25 kg/m² and a GWG until the 1^st GDM visit ≥ 10.3 kg (mean GWG), the risk for FWC > 90% and FACC > 90% was 5.3 and 4 times higher than in their counterparts.

Conclusions

A personalized fetal ultrasound surveillance guided by fetal sex, prepregnancy BMI and GWG may be beneficial in reducing adverse fetal and neonatal outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04767-z.

The Effect of Maternal US Nativity on Racial/Ethnic Differences in Fetal Growth

While racial/ethnic differences in fetal growth have been documented, few studies have examined whether they vary by exogenous factors, which could elucidate underlying causes. The purpose of this study was to characterize longitudinal fetal growth patterns by maternal sociodemographic, behavioral, and clinical factors and examine whether associations with maternal race/ethnicity varied by these other predictors. Between 2016 and 2019, pregnant women receiving prenatal care at NYU Langone Health (New York, New York) were invited to participate in a birth cohort study. Women completed questionnaires, and clinical data were abstracted from ultrasound examinations. Maternal characteristics were assessed in relation to fetal biometric measures throughout pregnancy using linear mixed models. Maternal race/ethnicity was consistently associated with fetal biometry: Black, Hispanic, and Asian women had fetuses with smaller head circumference, abdominal circumference, and biparietal diameter than White women. The associations between race/ethnicity and fetal growth varied by nativity for Asian women, such that the disparity between Asian and White women was much greater for US-born women than for foreign-born women. However, associations for Black and Hispanic women did not vary by nativity. While race/ethnicity-specific fetal growth standards have been proposed, additional work is needed to elucidate what could be driving these differences, including factors that occur in parallel and differentially affect fetal growth.

Early Exposure to Animals and Childhood Body Mass Index Percentile and Percentage Fat Mass

INTRODUCTION

A few studies have identified childhood animal exposure as associated with adiposity, but results are inconsistent and differ in timing.

METHODS

We conducted an observational cohort study of children ages 4-8 in the Environmental Influences on Child Health Outcomes [ECHO] study. The main exposure was having a dog in the home and/or regular contact with farm animals during the first year of life. Outcomes of interest were child BMI percentile (adjusted for gender and age) categorized as normal/underweight (<85^th percentile), overweight (85^th to <95^th), and obese (≥95^th), and percent fat mass (continuous). Associations were analyzed using multinomial logistic regression and multivariable linear regression, respectively, with and without multiple imputation.

RESULTS

First year animal exposure occurred in 245 of 770 (31.8%) children. Children with early animal exposure had 0.53 (95% CI: 0.28, 0.997) times the odds of being in the obese BMI category compared to those exposed to animals after controlling for covariates: maternal pre-pregnancy BMI, race/ethnicity, reported child activity level, receiving food assistance, age child began daycare (<1 year vs 1+), exclusively breastfed x6 months, and NICU admission (n=721). Children with early animal exposure had, on average, 1.5% (95% CI: -3.0, -0.1) less fat mass than exposed children after adjustment for maternal BMI, race/ethnicity, activity, food assistance, breastfeeding, and maternal education (n=548). Multiple imputation did not alter either result.

CONCLUSION

These results provide evidence that exposure to dogs or farm animals in the first year of life is associated with lower odds of obesity and lower percent fat mass in childhood.

Obesity and Maternal-Placental-Fetal Immunology and Health

Obesity rates in women of childbearing age is now at 29%, according to recent CDC reports. It is known that obesity is associated with oxidative stress and inflammation, including disruptions in cellular function and cytokine levels. In pregnant women who are obese, associated placental dysfunction can lead to small for gestational age (SGA) infants. More frequently, however, maternal obesity is associated with large for gestational age (LGA) newborns, who also have higher incidence of metabolic disease and asthma due to elevated levels of inflammation. In addition, anthropogenic environmental exposures to "endocrine disrupting" and "forever" chemicals affect obesity, as well as maternal physiology, the placenta, and fetal development. Placental function is intimately associated with the control of inflammation during pregnancy. There is a large amount of literature examining the relationship of placental immunology, both cellular and humoral, with pregnancy and neonatal outcomes. Cells such as placental macrophages and NK cells have been implicated in spontaneous miscarriage, preeclampsia, preterm birth, perinatal neuroinflammation, and other post-natal conditions. Differing levels of placental cytokines and molecular inflammatory mediators also have known associations with preeclampsia and developmental outcomes. In this review, we will specifically examine the literature regarding maternal, placental, and fetal immunology and how it is altered by maternal obesity and environmental chemicals. We will additionally describe the relationship between placental immune function and clinical outcomes, including neonatal conditions, autoimmune disease, allergies, immunodeficiency, metabolic and endocrine conditions, neurodevelopment, and psychiatric disorders.

Changes in Diet and Exercise in Pregnant Women after Diagnosis with Gestational Diabetes: Findings from a Longitudinal Prospective Cohort Study

BACKGROUND

Lifestyle changes are recommended for women diagnosed with gestational diabetes mellitus (GDM), yet there are few data available documenting whether women change their diet and exercise after GDM diagnosis.

OBJECTIVE

The aim of this study was to assess whether, and to what extent, pregnant women receiving usual prenatal care change their diet and exercise after a GDM diagnosis.

DESIGN

This study was a post-hoc secondary analysis using data from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies-Singletons (2009-2013), a prospective pregnancy cohort study.

PARTICIPANTS/SETTING

Pregnant US women without major chronic medical conditions were enrolled from 12 participating hospital centers at 8 to 13 weeks' gestation. Diet analyses were based on 5,194 dietary recalls from 1,371 women. Exercise analyses were based on 6,440 physical activity assessments from 1,875 women. GDM was ascertained from medical records according to Carpenter and Coustan criteria. Women completed 24-hour dietary recalls and exercise assessments at weeks 16 to 22, 24 to 29, 30 to 33, 34 to 37, and 38 to 41 (exercise only).

MAIN OUTCOME MEASURES

The main outcome was the diet and exercise change from before to after GDM diagnosis or screening.

STATISTICAL ANALYSES

Diet and exercise changes with 95% CIs from before to after GDM diagnosis or screening for women with and without GDM were estimated using weighted multivariable linear mixed models.

RESULTS

Women with GDM (n = 72) significantly reduced their total energy intake (-184 kcal/d; 95% CI -358 to -10 kcal/d) and carbohydrate intake (-47.6 g/d; 95% CI -71.4 to -23.7 g/d) from before to after GDM diagnosis; these changes were unique to women with GDM and not observed among women without GDM (n = 1,299). Women with GDM decreased intakes of juice (-0.4 cups/d; 95% CI -0.7 to -0.2 cups/d) and added sugar (-3.2 teaspoons/d; 95% CI -5.5 to -0.5 teaspoons/d) and increased cheese (0.3 cups/d; 95% CI 0.1 to 0.6 cups/d) and artificially sweetened beverages (0.2 cups/d; 95% CI 0.0 to 0.3 cups/d). Women with GDM (n = 84) did not change their exercise duration after diagnosis; women without GDM (n = 1,791) significantly decreased moderate (-19.5 min/wk; 95% CI -24.7 to -14.3 min/wk) and vigorous exercise (-8.8 min/wk; 05% CI -10.6 to -6.9 min/wk) after GDM screening.

CONCLUSIONS

Women with GDM made modest dietary improvements and maintained their prediagnosis exercise routine, yet opportunities remain to further improve dietary intake and exercise after a diagnosis of GDM.

Periconceptional maternal body mass index and the impact on post-implantation (sex-specific) embryonic growth and morphological development

OBJECTIVE

Women with obesity have an increased risk of pregnancy complications. Although complications generally present in the second and third trimester of pregnancy, most of them develop in the periconception period. Moreover, fetal sex also impacts pregnancy course and outcome. Therefore, our aim is to study (sex-specific) associations between periconceptional maternal body mass index (BMI) and embryonic growth and morphological development.

METHODS

A total of 884 women with singleton pregnancies were selected from the Rotterdam Periconception Cohort, comprising 15 women with underweight, 483 with normal weight, 231 with overweight and 155 with obesity. Longitudinal three-dimensional ultrasound examinations were performed at 7, 9, and 11 weeks of gestation for offline measurements of crown-rump length (CRL), embryonic volume (EV), and Carnegie stages. Analyses were adjusted for maternal age, parity, ethnicity, education, and periconceptional lifestyle.

RESULTS

A negative trend was observed for embryos of women with obesity (β_EV -0.03, p = 0.086), whereas embryonic growth and developmental trajectories in women with overweight were comparable to those with normal weight. Maternal underweight was associated with faster morphological development (β_Carnegie 0.78, p = 0.004). After stratification for fetal sex, it was demonstrated that female embryos of underweight women grow and morphologically develop faster than those of normal weight women (β_EV 0.13, p = 0.008; β_Carnegie 1.39, p < 0.001), whereas female embryos of women with obesity grow slower (β_EV -0.05, p = 0.027).

CONCLUSION

We found that periconceptional maternal underweight is associated with faster embryonic growth, especially in females. In contrast, female embryos of women with obesity grow slower than female embryos of women with normal weight. This may be the result of altered female adaptation to the postnatal environment. Future research should focus on strategies for optimizing preconceptional maternal weight, to reduce BMI-related pregnancy complications and improve the health of future generations.

Maternal Proinflammatory Adipokines Throughout Pregnancy and Neonatal Size and Body Composition: A Prospective Study

BACKGROUND

Increased maternal adiposity and inflammation have impacts on fetal growth.

OBJECTIVES

The purpose of this prospective study was to investigate the associations of 3 proinflammatory adipokines in pregnancy with neonatal anthropometry.

METHODS

In a sample of 321 US pregnant women from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singleton Cohort (NCT00912132), plasma IL-6, fatty acid binding protein-4 (FABP4), and chemerin were measured in plasma samples collected at 10-14, 15-26, 23-31, and 33-39 weeks of gestation. Generalized linear models were used to estimate associations of adipokines with neonatal weight, thigh, and crown-heel length, and skinfolds at birth. Models adjusted for age, race/ethnicity, education, nulliparity, prepregnancy BMI, and weeks of gestation at blood collection.

RESULTS

At each time point, higher IL-6 was associated with lower neonatal birthweight and thigh length. At 15-26 weeks of gestation, a 1 SD pg/mL increase in IL-6 was associated with -84.46 g lower neonatal birthweight (95% CI: -150.70, -18.22), -0.17 cm shorter thigh length (95% CI: -0.27, -0.07), -0.43 cm shorter crown-heel length (95% CI: -0.75, -0.10), and -0.75 mm smaller sum of skinfolds (95% CI: -1.19, -0.31), with similar associations at 23-31 and 33-39 weeks of gestation. There were no associations of FABP4 and chemerin with neonatal anthropometry.

CONCLUSIONS

Starting as early as 15 weeks of gestation, higher maternal IL-6 concentrations in pregnancy were associated with lower neonatal birthweight, thigh and crown-heel length, and skinfolds. These data provide insight into the relevance of maternal inflammatory markers with neonatal anthropometry.

The Impact of Maternal High-Fat Diet on Bone Microarchitecture in Offspring

The incidence of obesity in women of reproductive age has significantly increased over the past 100 years. There is a well-established connection between maternal obesity during pregnancy and an increased risk of developing non-communicable cardiometabolic diseases in her offspring. This mini-review focuses on evidence examining the effect of maternal high-fat diet (HFD) on skeletal development and bone health in later life in offspring. The majority of rodent studies indicate that maternal HFD generally negatively affects both embryonic bone development and bone volume in adult animals. Details surrounding the mechanisms of action that drive changes in the skeleton in offspring remain unclear, although numerous studies suggest that some effects are sex-specific. Human studies in this area are limited but also suggest that HFD during pregnancy may impair bone formation and increase fracture risk during childhood. Given the consequences of low bone mass and deranged bone microarchitecture for offspring, advances in our understanding of the developmental origins of bone health is critical in the battle against osteoporosis.

Routine ultrasound for fetal assessment before 24 weeks' gestation

BACKGROUND

Ultrasound examination of pregnancy before 24 weeks gestation may lead to more accurate dating and earlier diagnosis of pathology, but may also give false reassurance. It can be used to monitor development or diagnose conditions of an unborn baby. This review compares the effect of routine or universal, ultrasound examination, performed before 24 completed weeks' gestation, with selective or no ultrasound examination.  OBJECTIVES: To assess the effect of routine pregnancy ultrasound before 24 weeks as part of a screening programme, compared to selective ultrasound or no ultrasound, on the early diagnosis of abnormal pregnancy location, termination for fetal congenital abnormality, multiple pregnancy, maternal outcomes and later fetal compromise. To assess the effect of first trimester (before 14 weeks) and second trimester (14 to 24 weeks) ultrasound, separately.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, and the World Health Organization's International Clinical Trials Registry Platform (ICTRP) on 11 August 2020. We also examined the reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), quasi-RCTs, cluster-RCTs and RCTs published in abstract form. We included all trials with pregnant women who had routine or revealed ultrasound versus selective ultrasound, no ultrasound, or concealed ultrasound, before 24 weeks' gestation. All eligible studies were screened for scientific integrity and trustworthiness.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for eligibility and risk of bias, extracted data and checked extracted data for accuracy. Two review authors independently used the GRADE approach to assess the certainty of evidence for each outcome MAIN RESULTS: Our review included data from 13 RCTs including 85,265 women. The review included four comparisons. Four trials were assessed to be at low risk of bias for both sequence generation and allocation concealment and two as high risk. The nature of the intervention made it impossible to blind women and staff providing care to treatment allocation.  Sample attrition was low in the majority of trials and outcome data were available for most women. Many trials were conducted before it was customary for trials to be registered and protocols published. First trimester routine versus selective ultrasound: four studies, 1791 women, from Australia, Canada, the United Kingdom (UK) and the United States (US). First trimester scans probably reduce short-term maternal anxiety about pregnancy (risk ratio (RR) 0.80, 95% confidence interval (CI) 0.65 to 0.99; moderate-certainty evidence). We do not have information on whether the reduction was sustained.  The evidence is very uncertain about the effect of first trimester scans on perinatal loss (RR 0.97, 95% CI 0.55 to 1.73; 648 participants; one study; low-certainty evidence) or induction of labour for post-maturity (RR 0.83, 95% CI 0.50 to 1.37; 1474 participants; three studies; low-certainty evidence). The effect of routine first trimester ultrasound on birth before 34 weeks or termination of pregnancy for fetal abnormality was not reported. Second trimester routine versus selective ultrasound: seven studies, 36,053 women, from Finland, Norway, South Africa, Sweden and the US. Second trimester scans probably make little difference to perinatal loss (RR 0.98, 95% CI 0.81 to 1.20; 17,918 participants, three studies; moderate-certainty evidence) or intrauterine fetal death (RR 0.97, 95% CI 0.66 to 1.42; 29,584 participants, three studies; low-certainty evidence). Second trimester scans may reduce induction of labour for post-maturity (RR 0.48, 95% CI 0.31 to 0.73; 24,174 participants, six studies; low-certainty evidence), presumably by more accurate dating. Routine second trimester ultrasound may improve detection of multiple pregnancy (RR 0.05, 95% CI 0.02 to 0.16; 274 participants, five studies; low-certainty evidence). Routine second trimester ultrasound may increase detection of major fetal abnormality before 24 weeks (RR 3.45, 95% CI 1.67 to 7.12; 387 participants, two studies; low-certainty evidence) and probably increases the number of women terminating pregnancy for major anomaly (RR 2.36, 95% CI 1.13 to 4.93; 26,893 participants, four studies; moderate-certainty evidence). Long-term follow-up of children exposed to scans before birth did not indicate harm to children's physical or intellectual development (RR 0.77, 95% CI 0.44 to 1.34; 603 participants, one study; low-certainty evidence). The effect of routine second trimester ultrasound on birth before 34 weeks or maternal anxiety was not reported. Standard care plus two ultrasounds and referral for complications versus standard care: one cluster-RCT, 47,431 women, from Democratic Republic of Congo, Guatemala, Kenya, Pakistan and Zambia. This trial included a co-intervention, training of healthcare workers and referral for complications and was, therefore, assessed separately. Standard pregnancy care plus two scans, and training and referral for complications, versus standard care probably makes little difference to whether women with complications give birth in a risk appropriate setting with facilities for caesarean section (RR 1.03, 95% CI 0.89 to 1.19; 11,680 participants; moderate-certainty evidence).  The intervention also probably makes little to no difference to low birthweight (< 2500 g) (RR 1.01, 95% CI 0.90 to 1.13; 47,312 participants; moderate-certainty evidence). The evidence is very uncertain about whether the community intervention (including ultrasound) makes any difference to maternal mortality (RR 0.92, 95% CI 0.55 to 1.55; 46,768 participants; low-certainty evidence). Revealed ultrasound results (communicated to both patient and doctor) versus concealed ultrasound results (blinded to both patient and doctor at any time before 24 weeks): one study, 1095 women, from the UK. The evidence was very uncertain for all results relating to revealed versus concealed ultrasound scan (very low-certainty evidence).

AUTHORS' CONCLUSIONS

Early scans probably reduce short term maternal anxiety.  Later scans may reduce labour induction for post-maturity. They may improve detection of major fetal abnormalities and increase the number of women who choose termination of pregnancy for this reason. They may also reduce the number of undetected twin pregnancies. All these findings accord with observational data.  Neither type of scan appears to alter other important maternal or fetal outcomes, but our review may underestimate the effect in modern practice because trials were mostly  from relatively early in the development of the technology, and many control participants also had scans. The trials were also underpowered to show an effect on other important maternal or fetal outcomes.

Gestational diabetes: Implications for fetal growth, intervention timing, and treatment options

Maternal gestational diabetes mellitus (GDM) is one of the most common medical complications of pregnancy, which can adversely affect the short- and long-term health of mothers and newborns. In recent years, several studies have revealed the early impact of maternal hyperglycemia on fetal growth trajectory and birth weight abnormalities in GDM-exposed pregnancies. However, an intense debate continues regarding the mode and optimal timing of diagnosis and treatment of this condition. The purpose of this review is to provide a brief overview of the understanding of GDM and its implications for fetal growth, addressing the modulatory role of medical nutrition therapy and available pharmacological antidiabetic agents (i.e. insulin, metformin, and glyburide), and to identify gaps in current knowledge toward which future research should be directed.

Maternal Moderate-to-Vigorous Physical Activity before and during Pregnancy and Maternal Glucose Tolerance: Does Timing Matter?

PURPOSE

To assess prospective associations between moderate-to-vigorous physical activity (MVPA) from preconception through pregnancy and glucose metabolism.

METHODS

The sample consisted of 2,388 women from the NICHD Fetal Growth Studies-Singletons, which enrolled U.S. pregnant women between 8-13 weeks of gestation. Women recalled their MVPA in periconception (past 12 months, inclusive of 1st trimester), early-to-mid (13-20 weeks of gestation), and mid-to-late 2nd trimester (20-29 weeks). These data were obtained at study visits that occurred at enrollment (8-13 weeks) and at follow-up visits at 16-22 and 24-29 weeks. MVPA was recalled using the Pregnancy Physical Activity Questionnaire. Glucose challenge test and oral glucose tolerance test results and gestational diabetes diagnosis (defined by the Carpenter-Coustan criteria) were extracted from medical records. ANCOVA and Poisson regression with robust error variance were performed to estimate associations between MVPA and glucose concentrations and gestational diabetes risk, respectively, controlling for age, race/ethnicity, and pre-pregnancy body mass index.

RESULTS

Women achieving higher levels of MVPA (≥75th percentile; 760.5 MET·min·wk-1) in early-to-mid 2nd trimester had lower glucose concentrations (β = -3.9 mg/dL, 95%CI: -7.4,-0.5) compared to their least-active counterparts (≤25th percentile; ≤117.0 MET·min·wk-1). Women maintaining recommended levels of MVPA from preconception & 1st trimester through 2nd trimester (early-to-mid: β = -3.0 mg/dL, -5.9,-0.1; mid-to-late: β = -4.2 mg/dL,-8.4,-0.1) or maintaining sufficient activity throughout 2nd trimester exhibited lower glucose levels (β = -5.6 mg/dL, -9.8,-1.4) compared to their inactive counterparts. No statistically significant associations with gestational diabetes were observed.

CONCLUSIONS

These findings demonstrate that achieving MVPA of at least 760.0 MET·min·week-1 in early-to-mid 2nd trimester or maintaining at least 500 MET ·min·week-1 from preconception through 2nd trimester may be related to improved maternal glucose metabolism in the 2nd trimester.

Gestational diabetes mellitus, pre-pregnancy body mass index and gestational weight gain predicts fetal growth and neonatal outcomes

BACKGROUND

Gestational diabetes mellitus (GDM), body mass index (BMI) and gestational weight gain (GWG) are salient predictors of pregnancy-outcomes. However, findings on the association between GDM, BMI, and GWG with fetal growth measures are limited.

OBJECTIVE

The aim of this study was to investigate the effect of GDM on fetal growth measures and birth outcomes.

METHODS

All participants came from Tongji Maternal and Child health cohort, in which pregnant women were enrolled before 16 weeks of gestation and had their weights measured regularly during antenatal visits. GDM was diagnosed by oral glucose tolerance test (OGTT) during 24-28 weeks of gestation. Ultrasound measurements of fetal bi-parietal diameters (BPD), head circumferences (HC), abdominal circumferences (AC) and femur length (FL) before birth were collected and neonate outcomes were obtained from the hospital records. Odds ratios were calculated using logistic regression to assess the association of GDM, pre-pregnancy BMI, and GWG with fetal growth measures of ultrasound and birth outcomes, while controlling confounding.

RESULTS

Of 3253 singleton pregnant women, 293 (9.0%) were diagnosed with GDM, 357 (11.0%) were overweight before pregnancy, and 1995 (61.3%) had excessive GWG. GDM was associated with decreased intrauterine fetal growth measurements including BPD and AC. Maternal pre-pregnancy overweight was associated with increased fetal HC and neonatal birth weight and length, women gained excessive GWG had increased fetal growth measurements of BPD, HC, AC, FL, neonatal birth weight and length. Offspring of GDM women had increased odds of cesarean section 1.31 (1.03, 1.66) and preterm birth 2.02 (1.05, 3.91) in unadjusted models, but these associations disappeared after adjustment. Compared with neonate born to mothers with normal pre-pregnancy weight, those born to underweight mother had higher risk of SGA, and lower risk of cesarean section, LGA and macrosamia, whereas those born to overweight mother had increased risk of cesarean section, LGA and macrosamia. Compared with neonate born to mothers of adequate GWG, neonate of women with excessive GWG had elevated risk of cesarean section, LGA and macrosamia, but lower risk of preterm birth and SGA.

CONCLUSION

Pre-pregnancy BMI, GWG and GDM all associated with fetal growth and birth outcomes. The effect of GDM decreased after adjusting pre-pregnancy BMI and GWG. Early screening and management of GDM, preventing excessive GWG could help protect fetuses of GDM mothers from adverse birth outcomes.

Fetal growth velocity standards from the Fetal Growth Longitudinal Study of the INTERGROWTH-21st Project

BACKGROUND

Human growth is susceptible to damage from insults, particularly during periods of rapid growth. Identifying those periods and the normative limits that are compatible with adequate growth and development are the first key steps toward preventing impaired growth.

OBJECTIVE

This study aimed to construct international fetal growth velocity increment and conditional velocity standards from 14 to 40 weeks' gestation based on the same cohort that contributed to the INTERGROWTH-21st Fetal Growth Standards.

STUDY DESIGN

This study was a prospective, longitudinal study of 4321 low-risk pregnancies from 8 geographically diverse populations in the INTERGROWTH-21st Project with rigorous standardization of all study procedures, equipment, and measurements that were performed by trained ultrasonographers. Gestational age was accurately determined clinically and confirmed by ultrasound measurement of crown-rump length at <14 weeks' gestation. Thereafter, the ultrasonographers, who were masked to the values, measured the fetal head circumference, biparietal diameter, occipitofrontal diameter, abdominal circumference, and femur length in triplicate every 5 weeks (within 1 week either side) using identical ultrasound equipment at each site (4-7 scans per pregnancy). Velocity increments across a range of intervals between measures were modeled using fractional polynomial regression.

RESULTS

Peak velocity was observed at a similar gestational age: 16 and 17 weeks' gestation for head circumference (12.2 mm/wk), and 16 weeks' gestation for abdominal circumference (11.8 mm/wk) and femur length (3.2 mm/wk). However, velocity growth slowed down rapidly for head circumference, biparietal diameter, occipitofrontal diameter, and femur length, with an almost linear reduction toward term that was more marked for femur length. Conversely, abdominal circumference velocity remained relatively steady throughout pregnancy. The change in velocity with gestational age was more evident for head circumference, biparietal diameter, occipitofrontal diameter, and femur length than for abdominal circumference when the change was expressed as a percentage of fetal size at 40 weeks' gestation. We have also shown how to obtain accurate conditional fetal velocity based on our previous methodological work.

CONCLUSION

The fetal skeleton and abdomen have different velocity growth patterns during intrauterine life. Accordingly, we have produced international Fetal Growth Velocity Increment Standards to complement the INTERGROWTH-21st Fetal Growth Standards so as to monitor fetal well-being comprehensively worldwide. Fetal growth velocity curves may be valuable if one wants to study the pathophysiology of fetal growth. We provide an application that can be used easily in clinical practice to evaluate changes in fetal size as conditional velocity for a more refined assessment of fetal growth than is possible at present (https://lxiao5.shinyapps.io/fetal_growth/). The application is freely available with the other INTERGROWTH-21st tools at https://intergrowth21.tghn.org/standards-tools/.

New onset of restless legs syndrome in pregnancy in a prospective multiracial cohort: Incidence and risk factors

OBJECTIVE

To determine whether the incidence and risk factors of restless legs syndrome (RLS) in pregnancy differ by race/ethnicity, we estimated relative risks of demographic, socioeconomic, and nutritional factors in association with risk of any incident RLS in pregnancy in a cohort of 2,704 healthy pregnant women without prior RLS.

METHODS

Using data from the multicenter, multiracial National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singletons, we examined the incidence of RLS from early pregnancy to near delivery through up to 6 assessments. Multivariable Poisson models with robust variance were applied to estimate relative risks (RRs).

RESULTS

The cumulative incidence of RLS in pregnancy was 18.1% for all women, 20.3% for White women, 15.4% for Black women, 17.1% for Hispanic women, and 21.1% for Asian women. Among Hispanic women, older age (RR [reference ≤25 years]: 25-35 years, 1.51; 95% confidence interval [CI] 1.05-2.16; ≥35 years, 1.58; 95% CI 0.93-2.68), anemia (RR [reference no]: yes, 2.47; 95% CI 1.31-4.64), and greater total skinfolds of the subscapular and triceps sites, independent of body mass index (RR [reference quartile 1]: quartile 5, 2.54; 95% CI 1.30-4.97; p trend = 0.01) were associated with higher risk of RLS, while multiparity was associated with a lower risk (RR [reference nulliparity]: 0.69; 95% CI 0.50-0.96). In Black women, greater skinfolds and waist circumference were associated with higher risk of pregnancy RLS, although the trends were less clear.

CONCLUSIONS

The incidence of RLS in pregnancy was high and differed by race/ethnicity, which is likely accounted for by differences in other risk factors, such as age, parity, and nutritional factors.

Risk factors and time trends for isolated craniosynostosis

BACKGROUND

We sought to investigate associations between maternal/infant characteristics and isolated craniosynostosis as well as its subtypes sagittal, metopic, and coronal synostosis, and assess trends in the prevalence of these conditions.

METHODS

We identified cases in the Texas Birth Defects Registry from 1999 to 2014. We used Poisson regression to identify associations between maternal/infant characteristics and craniosynostosis. We used joinpoint regression and unadjusted Poisson regression to evaluate temporal trends. Finally, we computed adjusted Poisson models to evaluate whether temporal trends were evident after accounting for changes in the population distributions of maternal/infant characteristics over time.

RESULTS

Relative to all live births in the general population, cases were more frequently male or preterm. Mothers of cases were more frequently non-Hispanic white and more frequently obese. Non-Hispanic black or Hispanic maternal race/ethnicity was associated with a lower prevalence of all craniosynostosis subtypes. Previous live births were associated with sagittal synostosis; residence on the U.S.-Mexico border was associated with sagittal and coronal synostosis. The prevalence of any isolated craniosynostosis increased (average annual percent change estimated from joinpoint regression [AAPC]: 2.9%), as did the prevalences of sagittal (AAPC: 3.3%) and metopic synostosis (AAPC: 5.4%). In crude Poisson models, the same temporal trends were observed, however these were attenuated after adjusting for maternal/infant characteristics.

CONCLUSIONS

Prevalence of isolated craniosynostosis increased from 1999 to 2014. The largest AAPC was observed for metopic synostosis. Changes in the population distribution of associated maternal/infant characteristics may explain these trends.

Maternal Obesity Affects the Glucose-Insulin Axis During the First Trimester of Human Pregnancy

Background and objective: The maternal glucose-insulin axis is central for metabolic adaptations required for a healthy pregnancy. Metabolic changes in obese mothers in early pregnancy have been scantly described. Here we characterized the glucose-insulin axis in the first trimester of human pregnancy and assessed the effect of maternal obesity and fat mass. Methods: In this cross-sectional study, maternal blood samples (N = 323) were collected during voluntary pregnancy termination (gestational age 4+0-11+6 weeks) after overnight fasting. Smokers (N = 198) were identified by self-report and serum cotinine levels (ELISA). Maternal BMI (kg/m2) and serum leptin (ELISA) were used as proxy measures of obesity and maternal fat mass, respectively. BMI was categorized into under-/normal weight (BMI < 25.0 kg/m2), overweight (BMI 25.0-29.9 kg/m2) and obese (BMI ≥ 30.0 kg/m2), and leptin in tertiles (1st tertile: leptin < 6.80 ng/ml, 2nd tertile: leptin 6.80-12.89 ng/ml, 3rd tertile: leptin > 12.89 ng/ml). ISHOMA insulin sensitivity index was calculated from glucose and C-peptide (ELISA) serum concentrations. Analyses of covariance including multiple confounders were performed to test for differences in glucose, C-peptide and ISHOMA between gestational age periods, BMI and leptin groups. C-peptide and ISHOMA were log-transformed before analyses. Results: At weeks 7-9, fasting glucose and C-peptide levels were lower (P < 0.01 and P < 0.001, respectively) and insulin sensitivity higher (P < 0.001) than at weeks 4-6. Glucose levels were not significantly different between BMI or leptin categories. In contrast, C-peptide increased by 19% (P < 0.01) between the normal weight and the overweight group and by 39% (P < 0.001) between the overweight and obese group. In the leptin groups, C-peptide increased by 25% (P < 0.001) between the 1st and 2nd leptin tertile and by 15% (P < 0.05) between the 2nd and 3rd leptin tertile. ISHOMA decreased with higher BMI and fat mass. ISHOMA decreased by 18% (P < 0.01) between the normal weight and the overweight group and by 30% (P < 0.01) between the overweight and the obese group. In the leptin groups, ISHOMA decreased by 22% (P < 0.001) between the 1st and 2nd leptin tertile and by 14% (P < 0.05) between the 2nd and 3rd leptin tertile. Conclusions: At the group level, fasting glucose, C-peptide and insulin sensitivity dynamically change in the first trimester of human pregnancy. Maternal obesity is associated with higher C-peptide and lower insulin sensitivity at all periods in the first trimester of human pregnancy, while glucose is unaltered. These findings have implications for the timing of early gestational diabetes mellitus risk screening.

Guideline No. 391-Pregnancy and Maternal Obesity Part 1: Pre-conception and Prenatal Care

OBJECTIVE

This guideline will review key aspects in the pregnancy care of women with obesity. Part I will focus on pre-conception and pregnancy care. Part II will focus on team planning for delivery and Postpartum Care.

INTENDED USERS

All health care providers (obstetricians, family doctors, midwives, nurses, anaesthesiologists) who provide pregnancy-related care to women with obesity.

TARGET POPULATION

Women with obesity who are pregnant or planning pregnancies.

EVIDENCE

Literature was retrieved through searches of Statistics Canada, Medline, and The Cochrane Library on the impact of obesity in pregnancy on antepartum and intrapartum care, maternal morbidity and mortality, obstetrical anaesthesia, and perinatal morbidity and mortality. Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to September 2018. Grey (unpublished) literature was identified through searching the websites of health technology assessment and related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALIDATION METHODS

The content and recommendations were drafted and agreed upon by the authors. Then the Maternal-Fetal Medicine Committee peer reviewed the content and submitted comments for consideration, and the Board of the Society of Obstetricians and Gynaecologists of Canada (SOGC) approved the final draft for publication. Areas of disagreement were discussed during meetings, at which time consensus was reached. The level of evidence and quality of the recommendation made were described using the Evaluation of Evidence criteria of the Canadian Task Force on Preventive Health Care.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in these guidelines may increase obstetrical provider recognition of the issues affected pregnant individuals with obesity, including clinical prevention strategies, communication between the health care team, the patient and family as well as equipment and human resource planning. It is hoped that regional, provincial and federal agencies will assist in the education and support of coordinated care for pregnant individuals with obesity.

GUIDELINE UPDATE

SOGC guidelines will be automatically reviewed 5 years after publication. However, authors can propose another review date if they feel that 5 years is too short/long based on their expert knowledge of the subject matter.

SPONSORS

This guideline was developed with resources funded by the SOGC.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Placental function in maternal obesity

Maternal obesity is associated with pregnancy complications and increases the risk for the infant to develop obesity, diabetes and cardiovascular disease later in life. However, the mechanisms linking the maternal obesogenic environment to adverse short- and long-term outcomes remain poorly understood. As compared with pregnant women with normal BMI, women entering pregnancy obese have more pronounced insulin resistance, higher circulating plasma insulin, leptin, IGF-1, lipids and possibly proinflammatory cytokines and lower plasma adiponectin. Importantly, the changes in maternal levels of nutrients, growth factors and hormones in maternal obesity modulate placental function. For example, high insulin, leptin, IGF-1 and low adiponectin in obese pregnant women activate mTOR signaling in the placenta, promoting protein synthesis, mitochondrial function and nutrient transport. These changes are believed to increase fetal nutrient supply and contribute to fetal overgrowth and/or adiposity in offspring, which increases the risk to develop disease later in life. However, the majority of obese women give birth to normal weight infants and these pregnancies are also associated with activation of inflammatory signaling pathways, oxidative stress, decreased oxidative phosphorylation and lipid accumulation in the placenta. Recent bioinformatics approaches have expanded our understanding of how maternal obesity affects the placenta; however, the link between changes in placental function and adverse outcomes in obese women giving birth to normal sized infants is unclear. Interventions that specifically target placental function, such as activation of placental adiponectin receptors, may prevent the transmission of metabolic disease from obese women to the next generation.

Adipokines in early and mid-pregnancy and subsequent risk of gestational diabetes: a longitudinal study in a multiracial cohort

INTRODUCTION

Several adipokines are implicated in the pathophysiology of gestational diabetes mellitus (GDM), however, longitudinal data in early pregnancy on many adipokines are lacking. We prospectively investigated the association of a panel of adipokines in early and mid-pregnancy with GDM risk.

RESEARCH DESIGN AND METHODS

Within the National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singletons cohort (n=2802), a panel of 10 adipokines (plasma fatty acid binding protein-4 (FABP4), chemerin, interleukin-6 (IL-6), leptin, soluble leptin receptor (sOB-R), adiponectin, omentin-1, vaspin, and retinol binding protein-4) were measured at gestational weeks (GWs) 10-14, 15-26, 23-31, and 33-39 among 107 GDM cases (ascertained on average at GW 27) and 214 non-GDM controls. Conditional logistic regression was used to estimate ORs of each adipokine and GDM, controlling for known GDM risk factors including pre-pregnancy body mass index.

RESULTS

Throughout pregnancy changes in chemerin, sOB-R, adiponectin, and high-molecular-weight adiponectin (HMW-adiponectin) concentrations from 10-14 to 15-26 GWs were significantly different among GDM cases compared with non-GDM controls. In early and mid-pregnancy, FABP4, chemerin, IL-6 and leptin were positively associated with increased GDM risk. For instance, at 10-14 GWs, the OR comparing the highest versus lowest quartile (ORQ4-Q1) of FABP4 was 3.79 (95% CI 1.63 to 8.85). In contrast, in both early and mid-pregnancy adiponectin (eg, ORQ4-Q1 0.14 (0.05, 0.34) during 10-14 GWs) and sOB-R (ORQ4-Q1 0.23 (0.11, 0.50) during 10-14 GWs) were inversely related to GDM risk. At 10-14 GWs a model that included conventional GDM risk factors and FABP4, chemerin, sOB-R, and HMW-adiponectin improved the estimated prediction (area under the curve) from 0.71 (95% CI 0.66 to 0.77) to 0.77 (95% CI 0.72 to 0.82).

CONCLUSIONS

A panel of understudied adipokines including FABP4, chemerin, and sOB-R may be implicated in the pathogenesis of GDM with significant associations detected approximately 10-18 weeks before typical GDM screening.

Does cord blood leptin level mediate the association between neonatal body size and postnatal growth? Results from the EDEN mother-child cohort study

Background: Leptin is potentially involved in the correction of early postnatal growth of infants having deviated from their genetic trajectory in utero.Aim: To analyse the potential mediating role of cord blood leptin level in the association between neonatal anthropometry and early postnatal growth in the mother-child EDEN cohort.Subjects and methods: We included term newborns with information on leptin, birth weight and length, and weight and length SD-score changes over the first 2 months. The Baron and Kenny method was used to quantify the mediation contribution of leptin in the association between neonatal anthropometry and postnatal growth, considering several confounders. Analyses were stratified to consider sexual dimorphism.Results: A 1 SD higher birth weight was associated with a lower 2-months weight variation of 0.27 (0.18; 0.36) SD and a 0.16 (0.06; 0.26) SD, in boys and girls, respectively. Leptin explained 20% and 25% of these associations, respectively. Leptin did not mediate the association between birth length and birth-to-2 months length variation.Conclusion: Our results suggest that cord blood leptin may not be involved in the negative association between birth length and postnatal length growth but may play a modest mediating role in early postnatal catch-up or catch-down in weight.

Glycaemic status during pregnancy and longitudinal measures of fetal growth in a multi-racial US population: a prospective cohort study

BACKGROUND

The timepoint at which fetal growth begins to differ by maternal glycaemic status is not well understood. To address this lack of data, we examined gestational diabetes, impaired glucose tolerance, and early pregnancy glucose concentrations in relation to fetal growth trajectories.

METHODS

This cohort study included 2458 pregnant women from the NICHD Fetal Growth Studies-Singletons study, which took place between 2009 and 2013. Women were recruited from 12 clinical centres in the USA. Women aged 18-40 years without major chronic conditions when entering pregnancy were included and those with records of neither glucose screening test or glucose tolerance test were excluded from the study. Women were enrolled at gestational weeks 8-13 and randomly assigned to four ultrasonogram schedules (Group A; weeks 16, 24, 30, 34; Group B: weeks 18, 26, 31, 35, 39; Group C: weeks 20, 28, 32, 36; Group D: weeks 22, 29, 33, 37, 41) to capture weekly fetal growth. Gestational diabetes, impaired glucose tolerance, and normal glucose tolerance were defined by medical record review. Glucose was measured in a subsample of women at weeks 10-14. We modelled fetal growth trajectories using linear mixed models with cubic splines. This study is registered with ClinicalTrials.gov, NCT00912132.

FINDINGS

Of the 2458 women included in this study, 107 (4·4%) had gestational diabetes, 118 (4·8%) had impaired glucose tolerance, and 2020 (82·2%) had NGT. 213 women were excluded from the main analysis. The cohort with gestational diabetes was associated with a larger estimated fetal weight that started at week 20 and was significant at week 28-40 (at week 37: 3061 g [95% CI 2967-3164] for women with gestational diabetes vs 2943 g [2924-2962] for women with normal glucose tolerance, adjusted p=0·02). In addition, glucose levels at weeks 10-14 were positively associated with estimated fetal weight starting at week 23 and the association became significant at week 27 (at week 37: 3073 g [2983-3167] in the highest tertile vs 2853 g [2755-2955] in the lowest tertile, adjusted p=0·0009.

INTERPRETATION

Gestational diabetes was associated with a larger fetal size that started at week 20 and became significant at gestational week 28. Efforts to mitigate gestational diabetes-related fetal overgrowth should start before 24-28 gestational weeks, when gestational diabetes is typically screened for in the USA.

FUNDING

National Institutes of Health.

Comparing preoperative dating and postoperative dating for second-trimester surgical abortions

OBJECTIVES

To assess relationships between preoperative and postoperative dating of second-trimester surgical abortion.

STUDY DESIGN

We used a deidentified institutional database to extract demographic, dating and pathology data for surgical abortions performed at 14 to 23-6/7 weeks' gestational age (GA) from 9/2015 to 5/2017. We excluded women with multiple gestations, fetal anomalies and missing fetal biometric measurements. We assigned preoperative GA by ultrasonography for unknown last menstrual period (LMP) or when discrepancy between sonographic and LMP dating exceeded 7 days (<15-6/7 weeks), 10 days (16 to 21-6/7 weeks) or 14 days (22 to 23-6/7 weeks). We determined postoperative GA using fetal foot length pathology standards published by Streeter in 1920 and Drey et al. in 2005. We performed regression analysis to estimate the relationship between pre- and postoperative estimates of GA and to assess demographic effects on these estimates, and χ² tests to assess whether fetal foot lengths were concordant with, larger than or smaller than the expected range for the preoperative GA.

RESULTS

The 469 patients analyzed had a median preoperative GA of 19-4/7 weeks (range 14-0/7 to 23-6/7 weeks). Preoperative dating highly correlated with postoperative dating using both pathology standards (r²=0.95, p<.001), without any clinically relevant effect by body mass index (Streeter and Drey, p=.79), parity (Streeter p=.89; Drey p=.71), race (Streeter p=.06; Drey p=.07) or GA. Fetal foot lengths were larger than expected in 134 (28.6%) women using Streeter and 17 (3.6%) women using Drey standards (p<.001).

CONCLUSIONS

Preoperative dating and postoperative dating for second-trimester surgical abortion highly correlate. Use of Streeter standards results in more women with a postoperative GA greater than expected compared to Drey standards.

IMPLICATIONS

Increasing legal gestational age restrictions have placed additional burden on clinicians providing safe abortions, but guidelines on gestational age determination are lacking. Contemporary pathology standards consistent with modern practice and universally accepted by abortion providers and gynecologic pathologists are critical to our goal of safe and legal abortion provision.

Influences of Maternal Prepregnancy Obesity and Gestational Diabetes Mellitus on the Infant Gut Microbiome in Full-Term Infants

This review examines the current evidence of how prepregnancy obesity (PPO) and gestational diabetes mellitus (GDM) influence the newborn gut microbiome. Scientific gaps in the literature are described to guide future research in this area. The prevalence of PPO and GDM increased to 64% in the United States over the past decade. Prepregnancy obesity and GDM influence newborn gut microbiome and contribute to adverse short- and long-term outcomes in full-term infants. This review aims to discuss current research findings related to the associations between PPO and GDM, separately, and together, on infant gut microbiome outcomes, provide an overview of short-term and long-term outcomes, describe clinical relevance, and identify avenues for future scientific inquiry. This review found that PPO and GDM influence infant gut microbiomes. Infants born to women with PPO and GDM were found to have lower levels of diversity in gut microbiota than infants born to normal prepregnancy weight women and those born to women without GDM.

Fetal growth patterns in pregnancy-associated hypertensive disorders: NICHD Fetal Growth Studies

BACKGROUND

Fetal growth patterns in pregnancy-associated hypertensive disorders is poorly understood because prospective longitudinal data are lacking.

OBJECTIVE

The objective of the study was to compare longitudinal fetal growth trajectories between normotensive women and those with pregnancy-associated hypertensive disorders.

STUDY DESIGN

This is a study based on data from a prospective longitudinal cohort study of fetal growth performed at 12 US sites (2009-2013). Project gestational age was confirmed by ultrasound between 8 weeks 0 days and 13 weels 6 days, and up to 6 ultrasounds were performed across gestation. Hypertensive disorders were diagnosed based on 2002 American College of Obstetricians and Gynecologists guidelines and grouped hierarchically as severe preeclampsia (including eclampsia or HELLP [hemolysis, elevated liver enzymes, and low platelet count] syndrome), mild preeclampsia, severe gestational hypertension, mild gestational hypertension, or unspecified hypertension. Women without any hypertensive disorder constituted the normotensive group. Growth curves for estimated fetal weight and individual biometric parameters including biparietal diameter, head circumference, abdominal circumference, and femur and humerus length were calculated for each group using linear mixed models with cubic splines. Global and weekly pairwise comparisons were performed between women with a hypertensive disorder compared with normotensive women to analyze differences while adjusting for confounding variables. Delivery gestational age and birthweights were compared among groups.

RESULTS

Of 2462 women analyzed, 2296 (93.3%) were normotensive, 63 (2.6%) had mild gestational hypertension, 54 (2.2%) mild preeclampsia, 32 (1.3%) severe preeclampsia, and 17 (0.7%) unspecified hypertension. Compared with normotensive women, those with severe preeclampsia had estimated fetal weights that were reduced between 22 and 38 weeks (all weekly pairwise values of P < .008). Women with severe preeclampsia compared with those without hypertension also had significantly smaller fetal abdominal circumference between 23-31 and 33-37 weeks' gestation (weekly pairwise values of P < .04). Scattered weekly growth differences were noted on other biometric parameters between these 2 groups. The consistent differences in estimated fetal weight and abdominal circumference were not observed between women with other hypertensive disorders and those who were normotensive. Women with severe preeclampsia delivered significantly earlier (mean gestational age 35.9 ± 3.2 weeks) than the other groups (global P < .0001). Birthweights in the severe preeclampsia group were also significantly lower (mean -949.5 g [95% confidence interval, -1117.7 to -781.2 g]; P < .0001) than in the normotensive group.

CONCLUSION

Among women with pregnancy-associated hypertensive disorders, only those destined to develop severe preeclampsia demonstrated a significant and consistent difference in fetal growth (ie, smaller estimated fetal weight and abdominal circumference) when compared with normotensive women.

Effect of maternal sleep in late pregnancy on leptin and lipid levels in umbilical cord blood

OBJECTIVES

To study the impact of maternal sleep in late pregnancy on birth weight (BW) and leptin and lipid levels in umbilical cord blood.

STUDY DESIGN

A total of 277 healthy and singleton pregnancy women were recruited for participation in the Shanghai Sleep Birth Cohort Study (SSBC) during their 36-38 weeks of pregnancy, from May 2012 to July 2013. Maternal night sleep time (NST), sleep efficiency (SE), sleep onset latency (SOL) and the percentage of wake after sleep onset (WASO) in NST and midpoint of sleep (MSF) were measured by actigraphy for seven consecutive days. The leptin and lipid levels were determined in cord blood samples collected from the umbilical vein immediately after delivery. Birth information (birth weight, gender, delivery type, etc.) was extracted from medical records. A multivariable linear regression model was applied to examine the effect of maternal sleep in late pregnancy on newborn leptin and lipid levels in umbilical cord blood.

RESULTS

A total of 177 women and their infants were included in the analysis. Maternal mean NST was 7.03 ± 1.10 h in late pregnancy, and 48% had a shorter sleep time (NST < 7 h). The average maternal SE was 72.54% ± 9.66%. The mean percentage WASO/NST was 21.62% ± 9.98%; the average MSF was about 3:34 (0:53); and the SOL was 46.78 ± 36.00 min. After adjustment for confounders, both maternal NST and SE were found to be significantly associated with triglyceride levels (β = -0.219, p = 0.006; β = -0.224, p = 0.006) in umbilical cord blood; and maternal NST was also observed to have positive association with newborn leptin levels (β = 0.146, p = 0.047). However, we did not find significant association between other maternal sleep parameters in late pregnancy and leptin and lipid levels and birth weight.

CONCLUSIONS

Short sleep duration and poor sleep quality during late pregnancy were associated with newborn leptin and lipid levels, and efforts on improving maternal sleep during late pregnancy should be advocated for children's health.