Investigation of optimal gestational weight gain based on the occurrence of adverse pregnancy outcomes for Chinese women: a prospective cohort study

Associations between gestational weight gain under different guidelines and adverse birth outcomes: A secondary analysis of a randomized controlled trial in rural western China

Several gestational weight gain (GWG) guidelines have been established based on monocenter or multicenter researches. We aimed to examine the associations between categories of GWG under the Institute of Medicine (IOM) recommendation guideline, the Chinese National Health Commission (NHC) guideline, and weight-gain-for-gestational-age z-scores derived from the INTERGROWTH-21st Project and adverse birth outcomes. We used data from an antenatal micronutrient supplementation trial in rural western China between 2002 and 2006. Maternal weekly average GWG during the second and third trimesters was calculated and classified into inadequate, adequate and excessive GWG according to the IOM and NHC, respectively. Weight-gain-for-gestational-age z-scores derived from the INTERGROWTH-21st Project were grouped into three subgroups using two approaches: z-score percentile<25th, 25th to 75th, >75th and z-score <-1, -1 to 1, >1 SD. Infant birth weight and gestational age were measured using standard approaches. Generalized linear model with binomial family and logit link was applied to estimate the odds ratio (OR) and 95% confidential intervals (CI) for GWG categories and adverse birth outcomes. Among 1,239 women with normal weight (18.5 kg/m2 to 23.9 kg/m2) during early pregnancy, 18.0% and 34.2% were classified as adequate GWG according to IOM and NHC, respectively. Less than half of Chinese women reached optimal GWG by any recommendation guideline. According to NHC, excessive GWG showed a significant association with macrosomia (OR 3.75, 95% CI 1.03, 13.74), large-for-gestation-age (LGA) (OR 2.12, 95% CI 1.01, 4.45), and inadequate GWG was associated with post-term birth (OR 2.25, 95% CI 1.21, 4.16), compared with adequate GWG. Inappropriate GWG was associated with adverse birth outcomes even among women with normal weight during early pregnancy. The monitoring and interventions of weight status during pregnancy, especially for the second and third trimesters, are of great public health importance for optimal birth outcomes. Additionally, developing guideline of appropriate GWG ranges should account for the traits of regional population.

Gestational weight gain according to the Brazilian charts and its association with maternal and infant adverse outcomes

BACKGROUND

The lack of gestational weight gain (GWG) recommendations for low- and middle-income countries is a significant concern.

OBJECTIVES

To identify the ranges on the Brazilian GWG charts associated with lowest risks of selected adverse maternal and infant outcomes.

METHODS

Data from 3 large Brazilian datasets were used. Pregnant individuals aged ≥18, without hypertensive disorders or gestational diabetes were included. Total GWG was standardized to gestational age-specific z-scores according to Brazilian GWG charts. A composite infant outcome was defined as the occurrence of any of small-for-gestationa lage (SGA), large-forgestationa lage (LGA), or preterm birth. In a separate sample, postpartum weight retention (PPWR) was measured at 6 and/or 12 mo postpartum. Multiple logistic and Poisson regressions were performed with GWG z-scores as the exposure and individual and composite outcomes. GWG ranges associated with the lowest risk of the composite infant outcome were identified using noninferiority margins.

RESULTS

For the neonatal outcomes, 9500 individuals were included in the sample. For PPWR, 2602 and 7859 individuals were included at 6 and 12 mo postpartum, respectively. Overall, 7.5% of the neonates were SGA, 17.6% LGA, and 10.5% were preterm. Higher GWG z-scores were positively associated with LGA birth, whereas lower z-scores were positively associated with SGA births. The risk of the selected adverse neonatal outcomes were lowest (within 10% of lowest observed risk) when individuals with underweight, normal weight, overweight, or obesity gained between 8.8-12.6; 8.7-12.4; 7.0-8.9; and 5.0-7.2 kg, respectively. These gains correspond to probabilities of PPWR ≥5 kg at 12 mo of 30% for individuals with under and normal weight, and <20% for overweight and obesity.

CONCLUSIONS

This study provided evidence to inform new GWG recommendations in Brazil.

A prospective analysis of optimal total weight gain ranges and trimester-specific weight gain rates for Chinese pregnant women

BACKGROUND

Gestational weight gain (GWG) criteria recommended by the Institute of Medicine may not be appropriate for Asians. Our aims are to investigate the association between GWG and adverse pregnancy outcomes, and to propose optimal total GWG and rates of GWG for Chinese women.

METHODS

Prospective data of 51,125 mother-child pairs from 27 hospitals and community health care centers from Guizhou, Yunnan and Sichuan provinces in China between 2014 and 2018 were analyzed. Generalized Additive Models were performed to determine the associations of GWG with the risk of aggregated adverse outcomes (gestational diabetes mellitus, preeclampsia, cesarean delivery, stillbirth, preterm birth, macrosomia, large for gestational age, and small for gestational age). The range that did not exceed a 2.5% increase from the lowest risk of aggregated adverse outcomes was defined as the optimal GWG range.

RESULTS

Among all participants, U-shaped prospective association was found between GWG and the risk of aggregated adverse pregnancy outcomes. The optimal GWG range of 8.2-13.0 kg was proposed for underweight, 7.3-12.5 kg for normal weight, and 2.0-9.4 kg for overweight/obese women. Meanwhile, a higher GWG rate in the first two trimesters than that in the last trimester was suggested, except for overweight/obese women. After stratified by maternal age, mothers ≥35 years were suggested to gain less weight compared to younger mothers.

CONCLUSIONS

To keep a balance between maternal health and neonatal growth, optimal GWG ranges based on Asia-specific BMI categories was suggested for Chinese women with different pre-gravid BMIs and maternal ages.

Optimal gestational weight gain in Chinese pregnant women with gestational diabetes mellitus: A large retrospective cohort study

AIM

To examine the optimal gestational weight gain (GWG) for Chinese pregnant women with gestational diabetes mellitus (GDM) based on the Chinese-specific body mass index (BMI) classification.

METHODS

A retrospective cohort study was conducted using the 2017-2020 data from pregnant women with GDM in a tertiary hospital. A quadratic function model and the total predicted probability of adverse pregnancy outcomes were developed to obtain the optimal GWG. Differences in the incidence of adverse pregnancy outcomes between our optimal GWG recommendations and the Institute of Medicine (IOM) 2009 GWG guidelines were also analyzed.

RESULTS

A total of 8103 pregnant women with GDM were analyzed. Based on the Chinese-specific BMI classification, the optimal GWG range was 11.0-17.5 kg for underweight women, 3.7-9.7 kg for normal-weight women, -0.6 to 4.8 kg for overweight women, and - 9.8 to 4.2 kg for obese women. Excessive GWG had a higher risk of large for gestational age (LGA) (OR: 2.99, 95% CI: 2.42-3.70), macrosomia (OR: 2.35, 95% CI: 1.77-3.12), pre-eclampsia (OR: 1.91, 95% CI: 1.37-2.65), gestational hypertension (OR: 1.65, 95% CI: 1.24-2.19), cesarean section (OR: 1.29, 95% CI: 1.15-1.44), postpartum hemorrhage (OR: 1.29, 95% CI: 1.02-1.64); insufficient GWG had a higher risk of small for gestational age (OR: 1.82, 95% CI: 1.20-2.75). Compared to the IOM 2009 GWG guidelines, the prevalence of macrosomia, LGA, and postpartum hemorrhage were significantly lower in pregnant women following the implementation of our recommended GWG range (p < 0.05).

CONCLUSIONS

Compared to the IOM 2009 GWG recommendations, our optimal GWG recommendations for Chinese pregnant women were more sensitive.

Optimal Gestational Weight Gain for Women with Gestational Diabetes Mellitus — China, 2011–2021

What is already known about this topic?

Joint effects of gestational weight gain (GWG) and hyperglycemia on adverse pregnancy outcomes suggest that lower optimal GWG is optimal for women with gestational diabetes mellitus (GDM). However, there is still a lack of guidelines.

What is added by this report?

Optimal weekly GWG range after diagnosis of GDM for underweight, normal-weight, overweight, and obese women was 0.37-0.56 kg/week, 0.26-0.48 kg/week, 0.19-0.32 kg/week, and 0.12-0.23 kg/week, respectively.

What are the implications for public health practice?

The findings may be used to inform prenatal counseling regarding optimal gestational weight gain for women with gestational diabetes mellitus, and suggest the need for weight gain management.