Prepregnancy Obesity and Birth Outcomes

You'll never walk alone - The effects of walkability on pregnancy behaviors and outcomes

This study investigates the relationship between local walkability and physical activity and subsequent health outcomes among pregnant women - for whom walking is the recommended, and by far most common, form of exercise. Using an EPA measure of walkability at the county level (as well as other county-level characteristics) combined with rich individual-level data on pregnant women yields evidence that higher walkability translates into improvements in maternal and infant health outcomes as well as physical activity. Using the 2011 Natality Detail Files with geographic identifiers and controlling for the overall health of women in the community as well as the individual mother's pre-pregnancy BMI, we show that women residing in more walkable counties are less likely to experience preterm birth, low birth weight, gestational diabetes and hypertension. While one potential mechanism is through improved gestational weight gain, the evidence points to more general improvements in health as walkability does not seem to prevent excessive weight gain or macrosomic babies. Evidence that these general improvements derive at least in part from greater physical activity comes from analyses using the 2011 Behavioral Risk Factor Surveillance System, in which higher walkability translates into more physical activity among pregnant women (and also relative to their non-pregnant counterparts). Our study suggests more broadly that pregnant women's physical activity responds to factors that facilitate it and that such activity makes a difference to birth outcomes.

Effects of Nutritional and Social Factors on Favorable Fetal Growth Conditions Using Structural Equation Modeling

Poor birth outcomes such as low birth weight, low birth length and short gestational age, are public health concern issues in South Africa (SA). This study utilized structural equation modeling (SEM) to explore how nutritional and social factors contribute to favorable fetal growth conditions (FFGC) in pregnant women living with and without human immunodeficiency virus (HIV), in the Free State Province of SA. Sociodemographic characteristics, stress, health and nutrition-related information, and birth outcomes data were collected and analyzed from a subsample of 305 women enrolled in a cohort study from 2018−2020. Descriptive statistics were analyzed in R version 4.1.2 and SEM was conducted in Lavaan version 0.6−5. Higher gestational body mass index (GBMI) and income levels were associated with higher FFGC (p < 0.05). Household incomes were positively associated with dietary micronutrient quality (p = 0.002), GBMI (p = 0.012) and food security (p = 0.001). Low incomes (p = 0.004) and food insecurity (p < 0.001) were associated with higher stress, while social support was positively associated with food security status (p = 0.008). These findings highlight the complex interconnections between the social and nutritional factors that are associated with fetal growth conditions. Multisectoral community-based programs may be a useful strategy to address these challenges.

Maternal fish and shellfish consumption and preterm birth: a retrospective study in urban China

Preterm birth is the leading cause of perinatal mortality and morbidity. Some prospective cohort studies suggested that fish and shellfish consumption may affect the incidence of preterm birth. However, conflicting evidence exists on the relationship between fish and shellfish consumption and preterm birth. A total of 10 179 women from Gansu province were interviewed after delivery to collect information on their past intake of fish and shellfish using FFQ. Logistic regression models were used to estimate OR and 95 % CI to examine the association between fish and shellfish consumption and preterm birth and its clinical subtypes. Fish and shellfish consumption was associated with reduced risk of preterm birth (OR = 0·65, 95 % CI 0·56, 0·77). Increasing frequency of fish and shellfish consumption, compared with no fish and shellfish consumption, was associated with decreasing odds of preterm birth. Besides, increasing weekly total amount of fish and shellfish consumption, compared with no fish and shellfish consumption, was also associated with decreasing odds of preterm birth. Significant trend effect was also seen between fish and shellfish consumption and very preterm birth (P_{for trend} = 0·001) and spontaneous preterm birth (P_{for trend} = 0·003). Interaction was observed between total fish and shellfish consumption with maternal age (P_{for interaction} = 0·041) and pre-pregnancy BMI underweight (P_{for interaction} = 0·012). Our findings showed that maternal fish and shellfish consumption was associated with lower incidence of preterm birth.We recommend for the national guideline of ≥350 g/week of fish and shellfish consumption among pregnant women.

The effect of obesity in pregnancy and gestational weight gain on neonatal outcome in glucose-tolerant mothers

BACKGROUND

Most studies showing association between mothers with obesity in pregnancy or excessive gestational weight gain (GWG) and adverse neonatal outcome were cross-sectional or retrospective. Many included patients are with gestational diabetes mellitus (GDM), which is a strong risk factor for this adverse outcome. There are no prospective studies on this topic in Malaysia. This study aimed to examine prospectively the effects of obesity in pregnancy and GWG, independent of GDM, on neonatal outcome.

METHODS

Pregnant mothers in the first trimester, who presented to health clinics in Kuching, were screened. Mothers with existing diabetes mellitus or GDM were excluded using 75-g oral glucose tolerance test during the first and second trimesters. Participants with the first trimester BMI ≥ 23 kg/m2 were recruited as overweight/obese group, whereas those with BMI 18.5-22.9 kg/m2 were taken as the comparison group. At every trimester visit, mothers' weights were recorded. Babies' birth weight and occurrence of adverse neonatal outcome were documented.

RESULTS

There were 123 mothers recruited as overweight/obese group (mean BMI 29.0 kg/m2 ± 4.45) and 102 mothers as comparison group (mean BMI 20.4 kg/m2 ± 1.48). The number of low birth weight was similar between groups: 9.8% in overweight/obese group, 6.9% in the comparison group (p = 0.416). More than half of these babies were born to mothers with inadequate GWG (58.3% in obese group vs. 57.1% in control group, p = 0.077). There was no significant difference in the mean birth weight (3000 g ± 454.5 vs. 3038 g ± 340.8, p = 0.471), preterm delivery (8.13% vs. 3.92%, p = 0.193), and admission rate to neonatal intensive care unit (8.13% vs. 7.85%, p = 0.937) between groups. There was a positive correlation between the total GWG in overweight/obese group on baby's weight (r = 0.222, p = 0.013). Inadequate GWG was not correlated with lower birth weight (p = 0.052).

CONCLUSIONS

Obesity in pregnancy was not associated with poor neonatal outcome in this small sample of women in Malaysia. Total GWG showed a weak correlation with baby's birth weight in overweight/obese group.

Assessing the relationship between pregravid body mass index and risk of adverse maternal pregnancy and neonatal outcomes: prospective data in Southwest China

The relevance of pregestational body mass index (BMI) on adverse pregnancy outcomes remained unclear in Southwest China. This study aimed to investigate the overall and age-category specific association between pre-gestational BMI and gestational diabetes mellitus (GDM), preeclampsia, cesarean delivery, preterm delivery, stillbirth, macrosomia, and small-for-gestational age (SGA) or large-for-gestational age (LGA) neonates in Southwest China. Furthermore, it explores the relative importance of influence of pregravid BMI and maternal age on pregnancy outcomes. 51,125 Chinese singleton pregnant women were recruited as study subjects. Multiple logistic regression models were used to examine the influence of pre-pregnancy BMI on adverse pregnancy outcomes. Gradient boosting machine was used to evaluate the relative importance of influence of pregravid BMI and maternal age on pregnancy outcomes. It is found that women who were overweight or obese before pregnancy are at higher risk of adverse pregnancy outcomes except for SGA neonates, while pre-pregnancy underweight is a protective factor for GDM, preeclampsia, cesarean delivery, macrosomia and LGA, but not SGA. Younger mothers are more susceptible to GDM and macrosomia neonates, while older mothers are more prone to preeclampsia. Pre-pregnancy BMI has more influence on various pregnancy outcomes than maternal age. To improve pregnancy outcomes, normal BMI weight as well as relatively young maternal ages are recommended for women in child-bearing age.

Atlantic DIP: is weight gain less than that recommended by IOM safe in obese women with gestational diabetes mellitus?

BACKGROUND/OBJECTIVES

The Institute of Medicine (IOM) recommends gestational weight gain (GWG) of 5-9 kg in women with a body mass index (BMI) ≥ 30 kg/m². Debate continues as to whether GWG less than that recommended is safe in women with gestational diabetes mellitus (GDM). The study objective was to examine maternal and infant outcomes for obese women with GDM who lost weight or gained 0-5 kg during pregnancy.

SUBJECTS/METHODS

A 7-year retrospective cohort study of pregnancy outcomes for obese women with GDM recorded in the Atlantic Diabetes in Pregnancy database was conducted. We examined pregnancy outcomes for mothers with GDM and a BMI ≥ 30 who either lost weight or gained 0-5 kg (Group 1, n = 237) and women who gained 5-9 kg (Group 2, n = 77). We further divided groups 1 and 2 into women treated by diet only (GDM-D) (n = 120) and those requiring additional treatment with insulin (GDM-I) (n = 194).

RESULTS

GDM-D women in Group 1 were more likely to deliver earlier (38.9 vs 39.8 weeks, p < 0.01), to develop pregnancy induced hypertension (PIH) (15.4% v 0%; p = 0.02) or have a post-partum haemorrhage (PPH) (13.2% vs 0, p = 0.03) compared to women in Group 2. Rates of prematurity were higher in group 1 vs 2 (14.3% vs 0%, p = 0.03). However, further logistic regression analysis adjusted for smoking status, family history of diabetes, ethnicity and age determined no significant difference in maternal or infant outcomes for women in Group 1 compared to those in Group 2.

CONCLUSION

In our population, weight gain less than IOM guideline appears safe and is not associated with any further increase in adverse outcomes. However, validation through a prospective study with a larger obese GDM cohort is required before the findings presented here could be recommended for routine clinical use.

Nausea, vomiting and poor appetite during pregnancy and adverse birth outcomes in rural Nepal: an observational cohort study

Background

Nausea and vomiting are experienced by a majority of pregnant women worldwide. Previous studies have yielded conflicting results regarding their impact on birth outcomes and few studies have examined this relationship in settings with limited resources. We aimed to determine the effect of nausea, vomiting and poor appetite during pregnancy on birth outcomes in rural Nepal.

Methods

Observational cohort study using data collected in two randomized, community-based trials to assess the effect of influenza immunization during pregnancy on reproductive and respiratory outcomes among pregnant women and their offspring. Pregnant women in Sarlahi District, Nepal were recruited from 2011 to 2013. Exposure was defined as nausea, vomiting or poor appetite at any point during pregnancy and by trimester; symptoms were recorded monthly throughout pregnancy. Adverse outcomes were low birth weight (LBW), preterm birth and small for gestational age (SGA). Adjusted relative risks (aRR) with 95% CIs are reported from Poisson regressions with robust variance.

Results

Among 3,623 pregnant women, the cumulative incidence of nausea, vomiting or poor appetite was 49.5% (n = 1793) throughout pregnancy and 60.6% (n = 731) in the first trimester. Significantly higher aRRs of LBW and SGA were observed among women experiencing symptoms during pregnancy as compared to symptom free women (LBW: aRR 1.20; 95% CI 1.05 1.28; SGA: aRR 1.16; 95% CI 1.05 1.28). Symptoms in the first trimester were not significantly associated with any of the outcomes. In the second trimester, we observed significantly higher aRRs for LBW and SGA (LBW: aRR 1.17; 95% CI 1.01 1.36; SGA: aRR 1.16; 95% CI 1.05 1.29) and a significantly lower aRR for preterm birth (aRR 0.75; 95% CI 0.59 0.96). In the third trimester, we observed significantly higher aRRs for LBW and SGA (LBW: aRR 1.20; 95% CI 1.01 1.43; SGA: aRR 1.14; 95% CI 1.01 1.29).

Conclusions

Symptoms of nausea, vomiting or poor appetite during pregnancy are associated with LBW, SGA and preterm birth in a setting with limited resources, especially beyond the first trimester.

Trial registration

Prospectively registered at ClinicalTrials.gov on Dec 17, 2009 (NCT01034254).

Sleep Disturbance in Early Pregnancy, but Not Inflammatory Cytokines, May Increase Risk for Adverse Pregnancy Outcomes

BACKGROUND

It is unclear whether subjective or objective measures of sleep during pregnancy are more pertinent to pregnancy outcomes. Moreover, it is unclear as to whether subjective indices (i.e., those likely influenced by psychological thoughts and emotions) are more likely than objective measures to modify inflammatory cytokines.

METHOD

Subjective and objective measures of sleep were collected from 166 pregnant women. Sleep data, both aggregate and variability measures, from diary and actigraphy, were ascertained for three 2-week periods during early gestation (10-20 weeks). A fasting morning blood sample was assayed for the cytokines (IL-6, IFN-γ, and TNF-α). Sleep, stress, and depression questionnaires were also collected. Repeated measures ANOVAs, regression models, and independent t tests were used to analyze the data.

RESULTS

Diary-assessed total sleep time (p < .05) and actigraphy-assessed sleep latency (p = .05) were negatively associated with gestational age. Variability in actigraphy-assessed sleep latency (p < .01) was negatively associated with infant weight. None of the cytokines was associated with any of the outcomes. t tests revealed that those with a complication were older (p < .05) and had higher pre-pregnancy BMI (p < .05), higher self-reported stress (p < .05), and lower IFN-γ (p < .05).

CONCLUSION

Findings suggest that longer and more variable sleep latency, as well as shorter sleep duration, is associated with shorter gestational age or a lower birth weight infant. Overall, the findings suggest that among a low-risk, healthy sample of pregnant women, sleep disturbance does not pose a substantial risk for adverse delivery outcomes.

Prepregnancy Overweight and Obesity Are Associated with an Increased Risk of Preterm Birth in Chinese Women

INTRODUCTION

The association between obesity before pregnancy and preterm birth varies with age and ethnicity.

OBJECTIVE

To study the association between early body mass index (BMI) and risk of preterm birth in Chinese women.

METHODS

This was a hospital-based retrospective cohort study including 36,596 Chinese women who gave birth to a live singleton infant from 2015 to 2018. Women were classified as underweight (BMI <18.5), normal weight (BMI 18.5 to <23), overweight (BMI 23 to <27.5), or obese (BMI ≥27.5) according to the most recent criteria for Asian women. Multivariate log-binomial regression models were used to estimate the relative risks (RRs) and 95% confidence intervals (95% CIs) for preterm birth among different groups.

RESULTS

Compared to women with normal weight, women with overweight or obesity before pregnancy had an increased risk of preterm birth; the RRs and 95% CIs were 1.22 (95% CI: 1.08-1.37) and 1.30 (95% CI: 1.01-1.69), respectively. The greatest risk of extremely preterm birth was observed in obese women. The estimators were robust when considering the maternal age and rate of gestational weight gain (GWG) during pregnancy.

CONCLUSIONS

Women with overweight and obesity had an increased risk of preterm birth regardless of GWG in early pregnancy. Our study suggests that it is beneficial to lose weight before conception for both overweight and obese women who plan to become pregnant.

Weight-Related Concerns as Barriers to Exclusive Breastfeeding at 6 Months

BACKGROUND

Human milk is considered the gold standard for infant nutrition, but more data are needed that examine the constellation of weight-related concerns as barriers to exclusive breastfeeding.

RESEARCH AIMS

The aim of this study was to examine how mothers' concerns regarding their own and their infants' weight, as well as disordered eating behaviors, were associated with breastfeeding self-efficacy and exclusive breastfeeding at 6 months.

METHODS

A prospective, quantitative, and self-report online survey design was used. Participants included 206 women (88.30% White, 59.20% with graduate degrees), with a mean age of 33.04 years ( SD = 4.31 years) and a mean prepregnancy body mass index (BMI) of 24.80 kg/m² ( SD = 5.50 kg/m²), who had given birth within the past 6 months.

RESULTS

Participants who reported not exclusively breastfeeding at 6 months had significantly higher prepregnancy BMI ( p < .001), higher body dissatisfaction ( p = .003), more disordered eating ( p = .036), higher child weight concerns ( p < .001), and lower breastfeeding self-efficacy ( p < .001). Mediation modeling revealed a direct negative relationship between prepregnancy BMI and exclusive breastfeeding at 6 months ( p < .001). Indirect negative relationships between prepregnancy BMI and exclusive breastfeeding at six months via (a) body dissatisfaction, (b) disordered eating, and (c) child weight concern, as well as breastfeeding self-efficacy (entered as concurrent mediators), were all significant.

CONCLUSIONS

Mothers' weight, body image and eating concerns, concern regarding their children's weight, and breastfeeding self-efficacy may constitute critical barriers to exclusive breastfeeding at 6 months. Interventions to improve breastfeeding duration and confidence should target maternal body image and eating concerns.

Roles of insulin resistance and beta cell dysfunction in macrosomia among Chinese women with gestational diabetes mellitus

AIMS

The aim was to examine associations of insulin resistance and beta cell dysfunction with macrosomia in Chinese women with gestational diabetes mellitus (GDM).

METHODS

We performed a secondary analysis of 923 women with GDM enrolled in a randomized controlled trial in 2010-2012 in Tianjin, China. Insulin resistance and beta-cell function were estimated using Homeostasis model assessment. Binary logistic regression was used to obtain adjusted odds ratios (ORs) and 95% confidence intervals (CIs). A two-step adjustment scheme was used to control for effects of potential confounders.

RESULTS

A total of 138 women (16.5%) had excessive weight gain, 127 (7.3%) had macrosomia and 150 (16.3%) had a large for gestational age (LGA) infant. Compared to women in bottom tertile of insulin resistance, women in upper tertile had increased risk of excessive weight gain (OR: 4.32, 95%CI: 1.95-9.62), macrosomia and LGA (OR: 2.61, 95%CI: 1.20-5.69; 2.75, 95%CI: 1.35-5.62, respectively). The observed overall effects were mainly due to their large effect sizes among women with normal pre-pregnancy body weight. However, beta cell function was not found to be associated with either of them.

CONCLUSIONS

Increased insulin resistance during pregnancy was associated with excessive weight gain, macrosomia and LGA in Chinese women with GDM.

The impact of expanded health insurance coverage for unauthorized pregnant women on prenatal care utilization

OBJECTIVE

The objective of this study was to investigate the effect of expanding Medicaid health insurance coverage for unauthorized women on prenatal care utilization.

DESIGN AND SAMPLE

A natural experiment design was used. We examined the prenatal care utilization of 20,876 unauthorized women from Nebraska, which expanded Medicaid coverage for unauthorized women, and South Carolina, which has never expanded coverage.

MEASURES

Measurements of prenatal care utilization included adequate prenatal care using the Kotelchuck Index and the number of prenatal care visits. The policy independent variable of interest was an interaction between the policy years (2007-2009) and Nebraska residence. Demographic characteristics were included as covariates. Analysis entailed a difference-in-difference approach to compare prenatal care utilization by state, both before and after legislation was passed to fund care among unauthorized women in Nebraska.

RESULTS

Women with insurance coverage were more likely to utilize prenatal services. Unauthorized women living in Nebraska during Medicaid expansion were 28% more likely to receive adequate prenatal care (OR = 1.28, p < 0.01) and had about one more prenatal care visit (IRR = 1.05, p < 0.01) than women who did not have expanded Medicaid coverage.

CONCLUSIONS

Findings have important public health policy implications to support improved birth outcomes among native-born infants of unauthorized women.

Genome-wide approach identifies a novel gene-maternal pre-pregnancy BMI interaction on preterm birth

Preterm birth (PTB) contributes significantly to infant mortality and morbidity with lifelong impact. Few robust genetic factors of PTB have been identified. Such 'missing heritability' may be partly due to gene × environment interactions (G × E), which is largely unexplored. Here we conduct genome-wide G × E analyses of PTB in 1,733 African-American women (698 mothers of PTB; 1,035 of term birth) from the Boston Birth Cohort. We show that maternal COL24A1 variants have a significant genome-wide interaction with maternal pre-pregnancy overweight/obesity on PTB risk, with rs11161721 (PG × E=1.8 × 10-8; empirical PG × E=1.2 × 10-8) as the top hit. This interaction is replicated in African-American mothers (PG × E=0.01) from an independent cohort and in meta-analysis (PG × E=3.6 × 10-9), but is not replicated in Caucasians. In adipose tissue, rs11161721 is significantly associated with altered COL24A1 expression. Our findings may provide new insight into the aetiology of PTB and improve our ability to predict and prevent PTB.

The Influence of Asthma and/or Hay Fever on Pregnancy: Data from the 1995 National Survey of Family Growth

BACKGROUND

Asthma is associated with adverse pregnancy outcomes. At the same time there is a worldwide increase in asthma and hay fever.

OBJECTIVE

This study addresses whether asthma and/or hay fever adversely influence pregnancy outcomes.

METHODS

Data from the 1995 National Survey of Family Growth that include a history of diagnosed asthma, hay fever, and adverse pregnancy outcomes in 10,847 women representative of the US population aged 15 to 44 years were analyzed.

RESULTS

Women with the allergic phenotypes asthma and hay fever and hay fever only had no significant increase in adverse pregnancy outcomes (spontaneous pregnancy loss, preterm birth, infant low birth weight), whereas women with the nonatopic phenotype asthma only (without hay fever) did. The study did not evaluate endotypes.

CONCLUSIONS

This study provides new data that the allergic phenotypes, asthma and hay fever and hay fever only, are compatible with healthy pregnancy, whereas the nonatopic asthma phenotype, asthma only, adversely impacts pregnancy.

Body Mass Index as a Measure of Obesity: Racial Differences in Predictive Value for Health Parameters During Pregnancy

BACKGROUND

As a measure of obesity, body mass index (BMI; kg/m²) is an imperfect predictor of health outcomes, particularly among African Americans. However, BMI is used to guide prenatal care. We examined racial differences in the predictive value of maternal BMI for physiologic correlates of obesity, serum interleukin (IL)-6 and C-reactive protein (CRP), as well as cesarean section and infant birth weight.

METHODS

One hundred five pregnant women (40 European American, 65 African American) were assessed during the second trimester. BMI was defined as per prepregnancy weight. Electrochemiluminescence and enzyme-linked immunosorbent assays were used to quantify IL-6 and CRP, respectively. Birth outcomes were determined by medical record review.

RESULTS

Women of both races classified as obese had higher serum IL-6 and CRP than their normal-weight counterparts (ps ≤ 0.01). However, among women with overweight, elevations in IL-6 (p < 0.01) and CRP (p = 0.06) were observed among European Americans, but not African Americans (ps ≥ 0.61). Maternal obesity was a significantly better predictor of cesarean section among European Americans versus African Americans (p = 0.03) and BMI was associated with infant birth weight among European Americans (p < 0.01), but not African Americans (p = 0.94). Effects remained after controlling for gestational age at delivery, gestational diabetes, and gestational weight gain as appropriate.

CONCLUSIONS

BMI may be a less valid predictor of correlates of overweight/obesity among African Americans versus European Americans during pregnancy. This should be considered in epidemiological studies of maternal-child health. In addition, studies examining the comparative validity of alternative/complementary measures to define obesity in pregnancy are warranted to inform clinical care.