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

Qinzheng Chen; Zhen He; Yaxin Wang; Xuanjin Yang; Nana Liu; Suhan Zhang; Liangkun Ma; Xuezhong Shi; Xiaocan Jia; Yongli Yang; Yin Sun; Yuan He

doi:10.2147/DMSO.S449706

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

Diabetes Metab Syndr Obes. 2024 May 2:17:1911-1921. doi: 10.2147/DMSO.S449706. eCollection 2024.

Authors

Qinzheng Chen¹, Zhen He¹, Yaxin Wang², Xuanjin Yang², Nana Liu², Suhan Zhang², Liangkun Ma², Xuezhong Shi¹, Xiaocan Jia¹, Yongli Yang¹, Yin Sun², Yuan He³

Affiliations

¹ Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, People's Republic of China.
² Department of Obstetrics and Gynecology, National Clinical Research Center for Obstetric & Gynecologic Diseases, Peking Union Medical College (PUMC) Hospital, Chinese Academy of Medical Sciences (CAMS) and PUMC, Beijing, People's Republic of China.
³ National Human Genetic Resources Center, National Research Institute for Family Planning, Beijing, People's Republic of China.

Abstract

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 (β 0.010, 95% CI 0.001, 0.019) and fetal body weight (β 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.

Keywords: adverse neonatal outcomes; body mass index; cohort study; fasting plasma glucose; fetal growth; mediation analysis.

Grants and funding

This work was funded by the China Medical Board (Grant #20-380), the National Key Research and Development Program of China (No. 2016YFC1000102), the Central Public-interest Scientific Institution Basal Research Fund (2020GJZ03), and the Yili Foundation of Health Science (2021-Y04).