Mediating effect of gestational weight gain on the preventive effect of exercise during pregnancy on macrosomia: a randomized clinical trial.

OBJECTIVE: We sought to investigate the impact of individualized exercise guidance during pregnancy on the incidence of macrosomia and the mediating effect of gestational weight gain (GWG). DESIGN: A prospective randomized clinical trial. SETTING: A Hospital in Xingtai District, Hebei Province. POPULATION: Older than 20 years of age, mid-pregnancy, and singleton pregnant women without contraindications to exercise during pregnancy. METHODS: A randomized clinical trial was conducted from December 2021 to September 2022 to compare the effects of standard prenatal care with individualized exercise guidance on the incidence of macrosomia. MAIN OUTCOME MEASURE: Incidence of macrosomia. RESULTS: In all, 312 singleton women were randomized into an intervention group (N = 162) or a control group (N = 150). Participants who received individualized exercise guidance had a significantly lower incidence of macrosomia (3.73% vs. 13.61%, P = 0.002) and infants large for gestational age (9.94% vs. 19.73%, P = 0.015). However, no differences were observed in the rate of preterm birth (1.86% vs. 3.40%, P = 0.397) or the average gestational age at birth (39.14 ± 1.51 vs. 38.69 ± 1.85, P = 0.258). Mediation analysis revealed that GWG mediated the effect of exercise on reducing the incidence of macrosomia. CONCLUSION: Individualized exercise guidance may be a preventive tool for macrosomia, and GWG mediates the effect of exercise on reducing the incidence of macrosomia. However, evidence does not show that exercise increases the rate of preterm birth or affects the average gestational age at birth. TRIAL REGISTRATION: The trial is registered at www.clinicaltrails.gov [registration number: NCT05760768; registration date: 08/03/2023 (retrospectively registered)].

Effect of Maternal Pre-Pregnancy Body Mass Index on Longitudinal Fetal Growth and Mediating Role of Maternal Fasting Plasma Glucose: A Retrospective Cohort Study.

Purpose: To assess the impact of maternal pre-pregnancy body mass index (BMI) on longitudinal fetal growth, and the potential mediation effect of the maternal fasting plasma glucose in first trimester. Methods: In this retrospective cohort study, we collected pre-pregnancy BMI data and ultrasound measurements during pregnancy of 3879 singleton pregnant women who underwent antenatal examinations and delivered at Peking Union Medical College Hospital. Generalized estimation equations, linear regression, and logistic regression were used to examine the association between pre-pregnancy BMI with fetal growth and adverse neonatal outcomes. Mediation analyses were also used to examine the mediating role of maternal fasting plasma glucose (FPG) in first trimester. Results: A per 1 Kg/m² increase in pre-pregnancy BMI was associated with increase fetal body length Z-score (ß 0.010, 95% CI 0.001, 0.019) and fetal body weight (ß 0.017, 95% CI 0.008, 0.027). In mid pregnancy, pre-pregnancy BMI also correlated with an increase Z-score of fetal abdominal circumference, femur length (FL). Pre-pregnancy BMI was associated with an increased risk of large for gestational age and macrosomia. Mediation analysis indicated that the associations between pre-pregnancy BMI and fetal weight in mid and late pregnancy, and at birth were partially mediated by maternal FPG in first trimester (mediation proportion: 5.0%, 8.3%, 1.6%, respectively). Conclusion: Maternal pre-pregnancy BMI was associated with the longitudinal fetal growth, and the association was partly driven by maternal FPG in first trimester. The study emphasized the importance of identifying and managing mothers with higher pre-pregnancy BMI to prevent fetal overgrowth.

Weekly Weight Gain in Women with Gestational Diabetes Mellitus and Neonatal Birth Weight - China, 2011-2021.

What is already known about this topic?: Elevated gestational weight gain (GWG) during pregnancy among women diagnosed with gestational diabetes mellitus (GDM) is correlated with an increased instance of large for gestational age (LGA) and macrosomia. However, it remains uncertain whether managing weekly GWG following a GDM diagnosis positively impacts fetal birth weight. What is added by this report?: Our study found that GWG following GDM diagnosis correlates positively with the risk of LGA and macrosomia among all body mass index (BMI) subgroups, especially for overweight and obese women. What are the implications for public health practice?: The results of this research highlight the importance of enforcing a more stringent regulation on GWG on a weekly basis for overweight and obese women diagnosed with GDM, particularly when considering neonatal growth.

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.