Effects of pre-pregnancy body mass index and gestational weight gain on maternal and infant complications

Yin Sun,Yunli Chen,Suhan Zhang,Shuya Cai,Juntao Liu,Shuai Ma,Zhongzhou Shen,Yawen Wang,Sansan Wu,Yu Jiang,Liangkun Ma,Yongle Zhan,Yingjie Shi,Yahui Feng

doi:10.1186/s12884-020-03071-y

Abstract

BackgroundThe potential effects of pre-pregnancy body mass (BMI) and gestational weight gain (GWG) on pregnancy outcomes remain unclear. Thus, we investigated socio-demographic characteristics that affect pre-pregnancy BMIs and GWG and the effects of pre-pregnancy BMI and GWG on Chinese maternal and infant complications.Methods3172 women were enrolled in the Chinese Pregnant Women Cohort Study-Peking Union Medical College from July 25, 2017 to July 24, 2018, whose babies were delivered before December 31, 2018. Regression analysis was employed to evaluate the socio-demographic characteristics affecting pre-pregnancy BMI and GWG values and their effects on adverse maternal and infant complications.ResultsMultivariate logistic regression analysis revealed that age groups < 20 years (OR: 1.97), 25–30 years (OR: 1.66), 30–35 years (OR: 2.24), 35–40 years (OR: 3.90) and ≥ 40 years (OR: 3.33) as well as elementary school or education below (OR: 3.53), middle school (OR: 1.53), high school (OR: 1.40), and living in the north (OR: 1.37) were risk factors in maintaining a normal pre-pregnancy BMI. An age range of 30–35 years (OR: 0.76), living in the north (OR: 1.32) and race of ethnic minorities (OR: 1.51) were factors affecting GWG. Overweight (OR: 2.01) and inadequate GWG (OR: 1.60) were risk factors for gestational diabetes mellitus (GDM). Overweight (OR: 2.80) and obesity (OR: 5.42) were risk factors for gestational hypertension (GHp). Overweight (OR: 1.92), obesity (OR: 2.48) and excessive GWG (OR: 1.95) were risk factors for macrosomia. Overweight and excessive GWG were risk factors for a large gestational age (LGA) and inadequate GWG was a risk factor for low birth weights.ConclusionsOverweight and obesity before pregnancy and an excessive GWG are associated with a greater risk of developing GDM, GHp, macrosomia and LGA. The control of body weight before and during the course of pregnancy is recommended to decrease adverse pregnancy outcomes, especially in pregnant women aged < 20 or > 25 years old educated below university and college levels, for ethnic minorities and those women who live in the north of China.Trial registrationRegistered at Clinical Trials (NCT03403543), September 29, 2017.

Highlights

The potential effects of pre-pregnancy body mass (BMI) and gestational weight gain (GWG) on pregnancy outcomes remain unclear
Overweight and obesity before pregnancy and an excessive GWG are associated with a greater risk of developing gestational diabetes mellitus (GDM), gestational hypertension (GHp), macrosomia and large gestational age (LGA)
Socio-demographic characteristics affecting Body mass index (BMI) values before pregnancy and GWG Pre-pregnancy BMIs were classified into 4 types namely: underweight, normal, overweight and obese women

Summary

Introduction

The potential effects of pre-pregnancy body mass (BMI) and gestational weight gain (GWG) on pregnancy outcomes remain unclear. The pre-pregnancy BMI of women of childbearing ages has shown an upward trend in developed countries [1]. In China, the 2002 national nutrition survey revealed that being overweight (a BMI ≥ 24 kg/m2) and obese (a BMI ≥ 28 kg/m2) for women aged 18–44 reached 21.8 and 6.1%, respectively [2], and that there was an increasing trend in women of childbearing age [3]. Underweight pregnant women are at an increased risk of preterm birth (PB) and for delivering small-for-gestational-age (SGA) newborns [7, 8]. It is of particular relevance to study the effects of pre-pregnancy BMI and GWG on pregnancy and the newborn, and to develop a reasonable pregnancy weight control plan. Most of the current evidence on pre-pregnancy BMI and GWG values comes from Western or high income countries [16]

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