Impacts of pre-pregnancy body mass index, gestational diabetes mellitus and gestational weight gain on perinatal outcomes and mode of delivery / 中国新生儿科杂志

ABSTRACT

Objective:To study the impacts of pre-pregnancy body mass index (BMI), gestational diabetes mellitus (GDM) and gestational weight gain (GWG) on perinatal outcomes and mode of delivery.Methods:From November 2016 to December 2017, single-pregnancy women in early pregnancy (<13 weeks) regularly checked-up at our hospital were enrolled in this prospective cohort study and followed up until delivery. They were assigned into four groups according to pre-pregnancy BMI: obese group (≥28.0 kg/m 2), overweight group(24.0-<28.0 kg/m 2), normal group (18.5-<24.0 kg/m 2) and underweight group(<18.5 kg/m 2). A 75-g oral glucose tolerance test was performed at 24-28 weeks of pregnancy to screen for GDM. The optimal GWG was 11.0-16.0 kg for underweight group, 8.0-14.0 kg for normal group, 7.0-11.0 kg for overweight group and 5.0-9.0 kg for obesity group. The effects of pre-pregnancy BMI, GDM and GWG on perinatal outcomes and delivery mode were evaluated using multivariate logistic regression methods. Results:A total of 802 pregnant women were included. The incidences of pre-pregnancy overweight and obesity were 21.8% and 8.9%, respectively. The incidence of GDM was 14.1%. 57.2% of the participants experienced excessive GWG. The incidences of macrosomia, low birth weight and premature birth were 7.1%, 2.7% and 2.2%, respectively. The incidence of Cesarean delivery (C-section) was 37.7%. Pre-pregnancy obesity [adjusted odds ratio ( AOR)=4.355, 95% confidence interval ( CI) 1.900-9.980] and excessive GWG ( AOR=3.799, 95% CI 1.796-8.034) were independent risk factors for macrosomia. Excessive GWG was a protective factor for low birth weight ( AOR=0.279, 95% CI 0.084-0.928) and inadequate GWG was a risk factor for low birth weight ( AOR=10.954, 95% CI 3.594-33.382) and premature birth ( AOR=8.796, 95% CI 2.628-29.438). Compared with the normal group, overweight group had an increased risk of C-section ( AOR=1.817, 95% CI 1.119-2.949). Compared with pregnant women without pre-pregnancy overweight/obesity, GDM nor excessive GWG, any combination of two of the above-mentioned three factors increased the risks of macrosomia ( AOR=3.908, 95% CI 1.630-9.370) and C-section ( AOR=2.269, 95% CI 1.325-3.886). The risks of macrosomia and C-section were the highest when all three factors existed. Conclusions:Pre-pregnancy obesity and excessive GWG are independent risk factors for macrosomia and pre-pregnancy overweight is a risk factor of C-section. Exposure to any two of the three factors (pre-pregnancy overweight/obesity, GDM and excessive GWG) increases risks of macrosomia and C-section and the highest risk is observed when all three factors are present.