Association among pre-pregnancy body mass index, gestational weight gain and neonatal birth weight: a prospective cohort study in China

High-Density Lipoproteins-Cholesterol (HDL-C) in Women With Gestational Diabetes (GDM): A Predictor for Large Gestational Age (LGA) Babies

Introduction The present study aimed to evaluate the associations between the clinical and biochemical characteristics of women with gestational diabetes (GDM) and the incidence of large for gestational age (LGA) babies. Methods This cohort study included data collected during prenatal follow-up of GDM women from January 2008 to August 2022. Clinical and biochemical variables were compared among small (SGA), adequate (AGA), or large for gestational age (LGA) babies. Associations of the main variables with the incidence of LGA were determined by multiple regression analysis. Results Out of 659 women, 56 had LGA, 547 had AGA, and 56 had SGA babies. We observed differences in the means of age, pregestational body mass index (BMI), high-density lipoproteins-cholesterol (HDL-C) levels, gestational weight gain (GWG), and gestational age at birth according to LGA, AGA, and SGA (p < 0.05). All other variables were not different between the groups. The frequencies (%) and relative risk (RR) of LGA babies were evaluated according to HDL-C in the first tertile and/or obesity, with 12.2% and risk ratio (RR)=2.77 (95% confidence interval (CI) 1.35-5.69, p=0.005) if the women had obesity and HDL in the first tertile, 11.3% and RR=2.27 (95% CI 1.03-5.03, p=0.042) if only HDL in the first tertile was present, 10.9% and RR=2.68 (95% CI 1.31-5.48, p=0.007) if the women had only obesity, using as a reference group those women without obesity or HDL-C in the first tertile (4.6% and RR=1) adjusted for age, age at birth and GWG. Conclusion In women with GDM, lower levels of HDL-cholesterol during pregnancy, as well as pregestational obesity, seem to be good predictors of the occurrence of LGA babies.

Pre-pregnancy body mass index, gestational diabetes mellitus, and gestational weight gain: individual and combined effects on fetal growth

Background

Pre-pregnancy body mass index (BMI), gestational diabetes mellitus (GDM), and gestational weight gain (GWG) are interlinked and may play a complex role in fetal growth. We aimed to examine the relationship between pre-pregnancy BMI, GDM, GWG, and fetal growth outcomes and explore the contribution of GDM and GWG to the relationship between Pre-pregnancy obesity/overweight and large-for-gestational-age (LGA) in a prospective cohort.

Methods

We prospectively recruited women in the first trimester and having one-step GDM screened with a 75-g oral glucose tolerance test between 24 and 28 weeks of gestation (n = 802). Outcomes included LGA, small-for-gestational-age (SGA), and preterm birth. To assess the individual and cumulative associations between pre-pregnancy BMI, GDM, GWG, and these outcomes, we used multivariate logistic regression analysis. Furthermore, we employed structural equation modeling (SEM) to investigate the mediating role of GDM and excessive GWG in the correlation between pre-pregnancy overweight/obesity and LGA.

Results

Pre-pregnancy obesity, GDM, and excessive GWG were all independently associated with increased odds of LGA. Inadequate GWG was associated with higher odds of preterm birth. Compared with women unexposed to pre-pregnancy overweight/obesity, GDM, or excessive GWG, women exposed any two conditions had higher odds for LGA (AOR 3.18, 95% CI 1.25-8.11) and women with coexistence of all had the highest odds for LGA (AOR 8.09, 95% CI 2.18-29.97). The mediation analysis showed that GDM explained 18.60% (p < 0.05) of the total effect of pre-pregnancy overweight/obesity on LGA, and GWG explained 17.44% (p < 0.05) of the total effect.

Conclusion

Pre-pregnancy obesity/overweight, GDM, and excessive GWG are associated with higher odds of fetal growth disturbances as individual factors and when they co-exist. The effect of pre-pregnancy overweight/obesity on LGA is partially achieved through GDM and excessive GWG.

Maternal age-specific risks for adverse birth weights according to gestational weight gain: a prospective cohort in Chinese women older than 30

BACKGROUND

It is unclear whether the effects of abnormal gestational weight gain (GWG) on birth outcomes are differently in women with different maternal ages. This study aimed to investigate maternal age-specific association between GWG and adverse birth weights in Chinese women older than 30.

METHODS

19,854 mother-child dyads were selected from a prospective cohort study in Southwest China between 2019 and 2022. Logistic regression model was used to assess the association between GWG, which defined by the 2009 Institute of Medicine guidelines, and adverse birth weights including large- and small-for-gestational-age (LGA and SGA), stratified by maternal age (31-34 years and ≥ 35 years).

RESULTS

In both maternal age groups, excessive and insufficient GWG were associated with increased odds of LGA and SGA, respectively. After women were categorized by pre-pregnancy body mass index, the associations remained significant in women aged 31-34 years, whereas for women aged ≥ 35 years, the association between excessive GWG and the risk of LGA was only significant in normal weight and overweight/obese women, and the significant effect of insufficient GWG on the risk of SGA was only observed in underweight and overweight/obese women. Moreover, among overweight/obese women, the magnitude of the association between insufficient GWG and the risk of SGA was greater in those aged ≥ 35 years (31-34 years: OR 2.08, 95% CI 1.19-3.55; ≥35 years: OR 2.65, 95% CI 1.47-4.74), while the impact of excessive GWG on the risk of LGA was more pronounced in those aged 31-34 years (31-34 years: OR 2.18, 95% CI 1.68-2.88; ≥35 years: OR 1.71, 95% CI 1.30-2.25).

CONCLUSIONS

The stronger associations between abnormal GWG and adverse birth weights were mainly observed in women aged 31-34 years, and more attention should be paid to this age group.

Effects of prepregnancy dietary patterns on infant birth weight: a prospective cohort study

BACKGROUND

Maternal nutrition can have a profound effect on fetal growth, development, and subsequent infant birth weight. However, little is known regarding the influence of prepregnancy dietary patterns.

OBJECTIVES

This study aimed to explore the effects between prepregnancy dietary patterns on birth weight.

METHODS

This study included 911 singleton live-born infants from the Taicang and Wuqiang Mother-Child Cohort Study (TAWS). Baseline information and prepregnancy diet data were collected during early pregnancy. Newborn birth information was obtained from the Wuqiang County Hospital. Macrosomia, defined as a birth weight of ≥4000 g, and large for gestational age (LGA), defined as a birth weight higher than the 90th percentile for the same sex and gestational age, were the outcomes of interest. The dietary patterns were extracted using principal component analysis. Logistic regression models were used to investigate the association between prepregnancy dietary patterns (in tertiles) and macrosomia and LGA, and subgroup analysis was further explored by pre-pregnancy body mass index (BMI).

RESULTS

Four dietary patterns were identified based on 15 food groups. These patterns were named as "cereals-vegetables-fruits," "vegetables-poultry-aquatic products," "milk-meat-eggs," and "nuts-aquatic products-snacks." After adjusting for sociodemographic characteristics, pregnancy complications, and other dietary patterns, greater adherence to the "cereals-vegetables-fruits" pattern before pregnancy was associated with a higher risk of macrosomia (adjusted OR = 2.220, 95% CI: 1.018, 4.843), while greater adherence to the "nuts-aquatic products-snacks" pattern was associated with a lower risk of macrosomia (adjusted OR = 0.357, 95% CI: 0.175, 0.725) compared to the lowest tertile. No significant association was observed between prepregnancy dietary patterns and LGA. However, after subgroup analysis of pre-pregnancy BMI, "cereals-vegetables-fruits" pattern was associated with an increased risk of LGA in overweight and obese mothers (adjusted OR = 2.353, 95% CI: 1.010, 5.480).

CONCLUSIONS

An unbalanced pre-pregnancy diet increases the risk of macrosomia and LGA, especially in overweight or obese women before pre-pregnancy.

Composition of the maternal gastrointestinal microbiome as a predictor of neonatal birth weight

BACKGROUND

The biological mechanism by which the maternal gastrointestinal microbiota contributes to fetal growth and neonatal birth weight is currently unknown. The purpose of this study was to explore how the composition of the maternal microbiome in varying pre-gravid body mass index (BMI) groups are associated with neonatal birth weight adjusted for gestational age.

METHODS

Retrospective, cross-sectional metagenomic analysis of bio-banked fecal swab biospecimens (n = 102) self-collected by participants in the late second trimester of pregnancy.

RESULTS

Through high-dimensional regression analysis using principal components (PC) of the microbiome, we found that the best performing multivariate model explained 22.9% of the variation in neonatal weight adjusted for gestational age. Pre-gravid BMI (p = 0.05), PC3 (p = 0.03), and the interaction of the maternal microbiome with maternal blood glucose on the glucose challenge test (p = 0.01) were significant predictors of neonatal birth weight after adjusting for potential confounders including maternal antibiotic use during gestation and total gestational weight gain.

CONCLUSIONS

Our results indicate a significant association between the maternal gastrointestinal microbiome in the late second trimester and neonatal birth weight adjusted for gestational age. Moderated by blood glucose at the time of the universal glucose screening, the gastrointestinal microbiome may have a role in the regulation of fetal growth.

IMPACT

Maternal blood glucose in the late second trimester significantly moderates the relationship between the maternal gastrointestinal microbiome and neonatal size adjusted for gestational age. Our findings provide preliminary evidence for fetal programming of neonatal birth weight through the maternal gastrointestinal microbiome during pregnancy.

Pre-pregnancy body mass index and risk of maternal or infant complications with gestational diabetes mellitus as a mediator: A multicenter, longitudinal cohort study in China

AIMS

We explored the complex relationships between pre-pregnancy body mass index (pBMI) and maternal or infant complications and the mediating role of gestational diabetes mellitus (GDM) in these relationships.

METHODS

Pregnant women from 24 hospitals in 15 different provinces of China were enrolled in 2017 and followed through 2018. Propensity score-based inverse probability of treatment weighting, logistic regression, restricted cubic spline models, and causal mediation analysis were utilized. In addition, the E-value method was used to evaluate unmeasured confounding factors.

RESULTS

A total of 6174 pregnant women were finally included. Compared to women with a normal pBMI, obese women had a higher risk for gestational hypertension (odds ratio [OR] = 5.38, 95% confidence interval [CI]: 3.48-8.34), macrosomia (OR = 2.65, 95% CI: 1.83-3.84), and large for gestational age (OR = 2.05, 95% CI: 1.45-2.88); 4.73% (95% CI: 0.57%-8.88%), 4.61% (95% CI: 0.51%-9.74%), and 5.02% (95% CI: 0.13%-10.18%) of the associations, respectively, were mediated by GDM. Underweight women had a high risk for low birth weight (OR = 1.42, 95% CI: 1.15-2.08) and small for gestational age (OR = 1.62, 95% CI: 1.23-2.11). Dose-response analyses indicated that 21.0 kg/m² may be the appropriate tipping point pBMI for risk for maternal or infant complications in Chinese women.

CONCLUSION

A high or low pBMI is associated with the risk for maternal or infant complications and partly mediated by GDM. A lower pBMI cutoff of 21 kg/m² may be appropriate for risk for maternal or infant complications in pregnant Chinese women.

Maternal plasma vitamin D levels across pregnancy are not associated with neonatal birthweight: findings from an Australian cohort study of low-risk pregnant women

BACKGROUND

In utero environments can be highly influential in contributing to the development of offspring obesity. Specifically, vitamin D deficiency during pregnancy is associated with adverse maternal and child health outcomes, however its relationship with offspring obesity remains unclear. We assessed maternal vitamin D status across pregnancy, change in plasma vitamin D concentrations and associations with neonatal birthweight, macrosomia and large for gestational age.

METHODS

Women (n = 221) aged 18-40 years with singleton (low-risk) pregnancies, attending antenatal clinics at a tertiary-level maternity hospital were recruited at 10-20 weeks gestation. Medical history, maternal weight and blood samples at three antenatal clinic visits were assessed; early (15 ± 3 weeks), mid (27 ± 2 weeks) and late (36 ± 1 weeks) gestation. Maternal 25(OH)D was analysed from stored plasma samples via liquid chromatography-tandem mass spectrometry (LC/MS/MS). Neonatal growth parameters were collected at birth. Unadjusted and adjusted linear and logistic regression assessed associations of maternal vitamin D with birthweight, macrosomia and large for gestational age.

RESULTS

Mean plasma 25(OH)D increased from early (83.8 ± 22.6 nmol/L) to mid (96.5 ± 28.9 nmol/L) and late (100.8 ± 30.8 nmol/L) gestation. Overall 98% of women were taking vitamin D-containing supplements throughout their pregnancy. Prevalence of vitamin D deficiency (25(OH)D < 50 nmol/L) was 6.5%, 6.3% and 6.8% at early, mid and late pregnancy respectively. No statistically significant association was found between 25(OH)D or vitamin D deficiency at any timepoint with neonatal birthweight, macrosomia or large for gestational age.

CONCLUSIONS

Prevalence of vitamin D deficiency was low in this cohort of pregnant women and likely related to the high proportion of women taking vitamin D supplements during pregnancy. Maternal 25(OH)D did not impact offspring birth weight or birth size. Future studies in high-risk pregnant populations are needed to further assess maternal vitamin D status and factors in utero which promote early life obesity.

[Individualized Somatic Classification of Newborns Using Birth Weight Percentiles Based On Maternal Body Height and Weight (Results of a Validation Study)]

INTRODUCTION

Birth weight is influenced by maternal anthropometry. The SGA-rate of newborns of short and light mothers (<158 cm,<53 kg) and the LGA-rate of tall and heavy mothers (>177 cm,>79 kg) are overestimated. The LGA-rate of newborns of shorter mothers and the SGA-rate of taller mothers are underestimated. Individualized birth weight percentiles (IBWP) based on 18 maternal groups (6 groups of height combined with 3 groups of weight), sex and weeks of gestation have been published. The aim of this study is to validate IBWP by evaluating SGA-, AGA-, and LGA-rates using perinatal data.

METHODS

The validation study compares IBWP (1995 to 2000, n=2.2 million singletons) with percentile values from two German cohorts (i: 1995 to 2000; n=2.3 million and ii: 2007 to 2011, n=3.2 million singletons) using newborns from the Lower Saxony Perinatal Survey (n=0.56 million singleton newborns, 2001 to 2009). SGA-, AGA-, and LGA-rates were calculated using R statistical analysis.

RESULTS

Common percentile charts based on the total population 1995-2000 and 2007-2011 yielded SGA-rates among shorter mothers of 21.1 to 21.6% and LGA-rates of 2.0 to 3.1%. In taller mothers, SGA-rates were 3.3 to 3.5% and LGA-rates were 26.6 to 27.1%. IBWP achieved SGA-rates of 9.0% and LGA-rates of 11.4 to 11.6% in shorter mothers and SGA- and LGA-rates of 10% in taller mothers.

DISCUSSION

IBWP consider the maternal size for estimation of the fetal growth potential and achieve expected SGA- and LGA-rates of 10%. Consideration of individual growth potential avoids underestimation and overestimation of SGA- and LGA-rates. It aided analyses of birth weight with IBWP simplify the assessment of the nutritional status.

Analysis of the Influence of Pre-Pregnancy BMI and Weight Gain during Pregnancy on the Weight of Healthy Children during the First 2 Years of Life: A Prospective Study

Background: Increased pre-pregnancy maternal BMI (pBMI) and gestational weight gain (GWG) have been found to increase infants’ birthweight and result in the programming of child weight and impact its later weight gain. Aim: To assess the impact of pBMI and GWG on the weight of children from birth to 2 years of age and over the duration of breastfeeding. Methods: Single Centre observational prospective longitudinal cohort study. Data were collected from medical records, and medical history. The analysis of multiple linear and mixed models was involved. Findings: 20% of females were overweight, while 13% were obese before the pregnancy. An overall model, including gender and smoking, indicated a significant impact of pBMI category on a child’s birth mass (p = 0.01). The GWG category affected a child’s birth weight (p = 0.018, Effect size 0.41). pBMI did not affect the breastfeeding duration. Conclusion: pBMI and GWG correlate with birth weight and weight in neonatal period, however they become insignificant in later childhood. Weight assessment methods among children aged up to two years of age require standardization. Maternal weight before the pregnancy nor the weight gain during the pregnancy do not influence the length of breastfeeding. The biggest limitation was the small sample size and the failure to account for weight gain per trimester of pregnancy. Further research on a larger population should be continued.

Maternal alloimmune antibodies against HPA and HLA class I antigens are associated with reduced birthweight among healthy neonates delivered by Chinese women

INTRODUCTION

It is well known that HPA-1a antibodies lead to fetal and neonatal alloimmune thrombocytopenia (FNAIT), and an association with reduced birthweight in boys has been reported. Although it remains unclear whether HLA antibodies cause FNAIT, an association between HLA class I antibodies and reduced birthweight in FNAIT neonates has been observed. The aim of this study was to investigate the incidence of platelet antibodies among Chinese women and the impact of maternal alloimmune antibodies on birthweight among healthy neonates.

MATERIAL AND METHODS

In this retrospective observational cohort study, platelet antibody screening was performed among women hospitalized for delivery from March 2019 to November 2020. A portion of each serum sample was used to distinguish HLA class I antibodies from HPA antibodies. Based on neonatal sex, gestational age and maternal age, platelet antibody-negative women who were hospitalized for delivery during the same period were randomly selected as reference groups at a 1:1 ratio for comparisons of the birthweights of healthy neonates delivered by women who were positive or negative for platelet antibodies.

RESULTS

Among 15 156 women, 1008 (6.7%) were positive for platelet antibodies; the incidences of positive platelet antibody were 1.2%, 1.9%, 1.6% and 2.0% among women with 1, 2, 3 and >3 pregnancies, respectively. Among 787 platelet antibody-positive serum samples available for further analysis, 548 (69.6%) were positive for HLA class I antibodies bound to platelets, and 239 (30.4%) were positive for HPA antibodies. The average birthweight of healthy neonates delivered by women who were positive for platelet antibodies, HLA class I antibodies or HPA antibodies was 161-483 g lower than that of neonates delivered by women who were negative for these antibodies (P < 0.001). Regarding birthweight reduction, there was no significant difference among women who were positive for these antibodies or between boys and girls (P > 0.05).

CONCLUSIONS

This study is the first to report that maternal HPA and HLA class I antibodies are associated with reduced birthweight among healthy neonates delivered by Chinese women. This finding provides information for the study of the effect of maternal alloimmune antibodies on fetal development.

Analysis of the Weight Management Behavior of Chinese Pregnant Women: An Integration of the Protection Motivation Theory and the Information-Motivation-Behavioral Skills Model

Inappropriate gestational weight gain has become a public health concern that threatens maternal and child health. Pregnant women's ability to manage their weight during pregnancy directly impacts their weight gain. In this study, we integrated the protection motivation theory and the information-motivation-behavioral skills model to develop an integrative theoretical model suitable for pregnancy weight management and reveal significant explainable factors of weight management behaviors during pregnancy. Based on a cross-sectional survey of 550 pregnant women from Jiangsu province, we came up with our findings. The results showed that several factors influenced pregnancy weight management behavior. According to the research, information, self-efficacy, response costs, and behavioral skills were significantly associated with weight management behaviors during pregnancy, while behavioral skills were also significant mediators of information, self-efficacy, and behavior. Furthermore, the information related to pregnancy weight management had the biggest impact on weight management behavior during pregnancy. The results of the model fit were acceptable and the integrative model could explain 30.6% of the variance of weight management behavior during pregnancy, which implies that the integrative theoretical model can effectively explain and predict weight management behaviors during pregnancy. Our study provides practical implications for the integrative model in improving pregnancy weight management behavior and offers a theoretical base for the weight management of pregnant women.

Clinical Observation of Effects of Prepregnancy Body Mass Index and Weight Gain during Pregnancy on Neonatal Weight and Delivery Outcome

Objective. The increase of BMI before pregnancy and during pregnancy will lead to hypertensive disorder in pregnancy (HDP) and abnormal glycolipid metabolism, as well as increase the risk of neonatal weight abnormalities and adverse pregnancy outcome. This study retrospectively analyzed the clinical data of 358 women who were admitted to the obstetrics department of our hospital from January 2018 to July 2019. And the relationship between prepregnancy BMI, BMI increase during pregnancy and delivery methods, postpartum hemorrhage, neonatal weight, premature delivery, neonatal asphyxia, gestational diabetes mellitus (GDM), and hypertension during pregnancy (HDP) was observed and compared. The results show that both high BMI before pregnancy and excessive weight gain during pregnancy can lead to the incidence of abnormal birth weight and adverse birth outcome increase. Therefore, in order to reduce the incidence of neonatal weight abnormalities and adverse birth outcomes and to prevent the adverse effects during pregnancy and postpartum, clinically, obese women should be guided to eat according to reasonable diet and exercise to control their weight.

Effect of Orlistat on Live Birth Rate in Overweight or Obese Women Undergoing IVF-ET: A Randomized Clinical Trial

CONTEXT

Obesity management prior to infertility treatment remains a challenge. To date, results from randomized clinical trials involving weight loss by lifestyle interventions have shown no evidence of improved live birth rate.

OBJECTIVE

This work aimed to determine whether pharmacologic weight-loss intervention before in vitro fertilization and embryo transfer (IVF-ET) can improve live birth rate among overweight or obese women.

METHODS

We conducted a randomized, double-blinded, placebo-controlled trial across 19 reproductive medical centers in China, from July 2017 to January 2019. A total of 877 infertile women scheduled for IVF who had a body mass index of 25 or greater were randomly assigned to receive orlistat (n = 439) or placebo (n = 438) treatment for 4 to 12 weeks. The main outcome measurement was the live birth rate after fresh ET.

RESULTS

The live birth rate was not significantly different between the 2 groups (112 of 439 [25.5%] with orlistat and 112 of 438 [25.6%] with placebo; P = .984). No significant differences existed between the groups as to the rates of conception, clinical pregnancy, or pregnancy loss. A statistically significant increase in singleton birth weight was observed after orlistat treatment (3487.50 g vs 3285.17 g in the placebo group; P = .039). The mean change in body weight during the intervention was -2.49 kg in the orlistat group, as compared to -1.22 kg in the placebo group, with a significant difference (P = .005).

CONCLUSION

Orlistat treatment, prior to IVF-ET, did not improve the live birth rate among overweight or obese women, although it was beneficial for weight reduction.

Prenatal Exercise and Cardiovascular Health (PEACH) Study: Impact on the Vascular System

PURPOSE

Healthy pregnancy is typically associated with favorable vascular adaptations to both structure and function of the peripheral arteries. Exercise is independently associated with improvements in peripheral vascular health; however, the impact of exercise on prenatal adaptations is unclear. Therefore, we hypothesized that a structured aerobic exercise intervention between the second and third trimester (TM2 and TM3, respectively) of pregnancy would augment the already-positive changes in vascular outcomes.

METHODS

We recruited 59 inactive pregnant women (<20 weeks gestation) and randomized them into control (standard care; n = 28) or exercise (moderate intensity aerobic exercise, 3-4 days/week, 25-40 minutes, 14 ± 1 weeks; n = 31) conditions. Before and after the intervention all women completed comprehensive peripheral vascular assessment, which included blood markers of vascular health, carotid distensibility metrics, measures of arterial stiffness (pulse wave velocity; PWV), and [superficial] femoral artery reactivity during cold pressor test (CPT).

RESULTS

Carotid artery diameter increased from 6.5 mm to 6.9 mm (p < 0.001) strain (%)decreased from 9.9% to 8.4% (p < 0.001). Carotid artery blood flow, compliance and distensibility coefficients, stiffness (β), distensibility (1/β), and Elastic modulus were not different across gestation. PWV was not different across gestation. Superficial femoral artery diameter was increased from 5.4 mm to 5.6 mm (p = 0.004) while blood flow, conductance, and resistance at rest and during CPT were not different across gestation. None of our measures of vascular health were impacted by exercise.

CONCLUSION

We did not observe an impact of aerobic exercise on altering the changes across pregnancy in blood vessel health. However, the present study was conducted in women who were overall at low risk for developing gestational hypertension and should be interpreted with caution. Future work in high-risk women is needed.