Examining the effects of second-and third-trimester gestational weight gain rates on the perinatal outcomes among Chinese twin pregnancies: a retrospective cohort study

BACKGROUND: This paper investigated how second- and third-trimester gestational weight gain relates to perinatal outcomes among normal weight women with twin pregnancies in Fujian, China. METHODS: A retrospective study examining the medical records of 931 normal weight twin-pregnant women was conducted in Fujian Maternity and Child Health Hospital from 2014 to 2018.The 2(nd) and 3(rd)trimester weekly weight gain rates were calculated, and women were categorized as gaining below, within, or above the 2009 Institute of Medicine (IOM) recommended rates. The association between the trimester-specific weight gain rate and perinatal outcome was determined by traditional regression analysis among groups. RESULTS: A total of 25.9%, 19.8% and 54.3% of women had rates of weight gain across the 2(nd) and 3(rd) trimesters less than, greater than or within the recommended rates respectively. Multivariate logistic regression analysis showed that weight gain greater than the recommended rate in the 2(nd) trimester was associated with a decreased risk of preeclampsia (aOR:0.489,95%CI:0.289 ~ 0.974). Weight gain less than the recommended rate of weight gain in the 3(rd) trimester was associated with increased risks of premature delivery(aOR:2.079, 95%CI:1.467 ~ 2.968), gestational diabetes mellitus (aOR: 2.048, 95%CI:1.411 ~ 2.971), intrahepatic cholestasis syndrome (aOR:3.015,95%CI: 1.058 ~ 8.587), pre-labour rupture of membrane (aOR: 1.708,95%CI: 1.169 ~ 2.493), average twin birth weight < 2500 g(aOR:1.532,95%CI: 1.125 ~ 2.084) and neonatal respiratory distress syndrome (aOR:4.934,95%CI:1.626 ~ 15.083) and was associated with decreased risks of caesarean section (aOR:0.589,95%CI:0.386 ~ 0.898) and preeclampsia (aOR:0.471, 95%CI:0.274 ~ 0.808). In addition, weight gain greater than the recommended rate of weight gain in the 3(rd) trimester was associated with increased risks of premature delivery (aOR:1.589,95%CI:1.428 ~ 2.951) and gestational hypertension (aOR:2.137,95% CI:1.034 ~ 4.415) as well as preeclampsia (aOR:2.246, 95%CI:1.462 ~ 3.452). The stratified analysis of weight gain in the 3(rd) trimester showed that there was no significant difference in the incidence of adverse pregnancy outcomes compared to the 2(nd) trimester weight gain groups. CONCLUSIONS: While this study showed that a gestational weight gain rate above or below the recommendation in the 3(rd) trimester was associated with some adverse maternal and neonatal outcomes, further prospective and multicentre studies are required to explore alternate ranges of gestational weight gain rates in twin pregnancies.