Association Between Gestational Weight Gain And Spontaneous Preterm Birth In Chinese Women With Twin Pregnancies

The studies on the association between maternal gestational weight gain (GWG) and spontaneous preterm birth (SPTB) in twin pregnancies are limited and inconsistent. There are no standardized guidelines for GWG in twin pregnancies in China. This retrospective cohort study included 1510 women who delivered living twins from January 1, 2015 to December 31, 2019. The basic demographics and outcomes of mothers and neonates were listed, and logistic regression was used to analyze the relationship between GWG and SPTB in the total population and different subgroups. In the overall population, 464 (30.7%) women had inadequate GWG, and 316 (20.9%) women had excess GWG. Compared to women with adequate GWG, women with inadequate GWG had a significantly higher risk of SPTB (adjusted odds ratio [aOR]: 2.46, 95% CI [1.92, 3.15]), while women with excess GWG also had a significantly higher risk of SPTB (aOR: 1.48, 95% CI [1.12, 1.95]). Both inadequate GWG and excess GWG had a significantly higher risk of SPTB in normal-weight women and women with dichorionic diamniotic twins. Only IGWG was significantly associated with SPTB in women with monochorionic diamniotic twins and underweight women. Our findings indicate that inadequate GWG and excess GWG were significantly associated with a higher risk of SPTB, providing an empirical basis for establishing weight gain guidelines for women with twin pregnancies in China.