Maternal weight gain during pregnancy in obese women and its relationship with adverse pregnancy outcomes / 中华围产医学杂志

ABSTRACT

Objective:To analyze the maternal gestational weight gain (GWG) in women with pre-pregnancy obesity and its relationships with adverse pregnancy outcomes.Methods:This retrospective cohort study recruited 513 obese women (pre-pregnancy body mass index ≥30 kg/m 2) with singleton pregnancy in Beijing Obstetrics and Gynecology Hospital, Capital Medical University from January 2014 to December 2016. All participants were divided into three groups according to GWG inadequate (GWG<5 kg, n=83), adequate (5 kg≤GWG≤9 kg, n=154), and excessive (GWG>9 kg, n=276) groups. Chi-square test, Fisher's exact test, Kruskal-Wallis test, and Mann-Whitney U test were used to compare the clinical data among the three groups, including GWG, pregnancy and neonatal outcomes, and labor process. Multivariate logistic regression was performed to analyze the association between maternal GWG and main pregnancy complications associated with obesity. Results:(1) Among 238 participants who gained more than 2.0 kg in the first trimester, 75.6% (180/238) were in the excessive group, while the rate was 34.9%(96/275) among the participants who gained less than 2.0 kg. (2) Postpartum body mass index retention (body mass index at six weeks postpartum minus pre-pregnancy body mass index) was the highest in the excessive group, followed by the adequate group and the inadequate group [0.8 kg/m 2 (0.0-2.2 kg/m 2) vs -0.7 kg/m 2 (-1.6 to 0.0 kg/m 2) vs -2.5 kg/m 2 (-3.2 to -1.5 kg/m 2), all P<0.05]. (3) The rates of primary cesarean section in the inadequate and adequate groups were 29.9% (20/67) and 32.6% (42/129), which were lower than that in the excessive group [43.3% (104/240), χ2=3.955 and 4.047, both P<0.05]. There were no statistically significant differences in the incidence of gestational hypertension, small/large for gestational age, or other major adverse pregnancy outcomes among the three groups (all P>0.05). The weight gain in the first trimester and before the oral glucose tolerance test were not correlated with gestational diabetes mellitus (GDM) ( aOR=1.038, 95% CI 0.986-1.094, P=0.157; aOR=1.055, 95% CI 1.000-1.113, P=0.051). The maternal weight gain of women with GDM during the 2nd, the 3rd, and the whole trimesters were lower than women without GDM respectively [3.0 kg (1.3-4.0 kg) vs 3.0 kg (2.0-5.0 kg), 4.0 kg (2.0-6.0 kg) vs 6.0 kg (4.0-8.0 kg), 9.0 kg (5.0-12.0 kg) vs 10.7 kg (7.5-15.0 kg); Z =-2.938, -6.352 and-4.104, all P<0.01]. Conclusions:In women with pre-pregnancy obesity, the first trimester is the critical window to control maternal GWG. GWG guidelines recommended by the Institute of Medicine could help to reduce the weight retention at six weeks postpartum, but couldn't reduce the risk of GDM, gestational hypertension, small/large for gestational age, or other major adverse pregnancy outcomes.