Gestational weight trajectory and risk of adverse pregnancy outcomes among women with gestational diabetes mellitus: A retrospective cohort study.

The aim of this study was to explore gestational weight gain (GWG) trajectories and their associations with adverse pregnancy outcomes. A retrospective cohort study including 11,064 women with gestational diabetes mellitus (GDM) was conducted between 2015 and 2019 in China. The latent class trajectory model was used to identify GWG trajectories, and logistic regression was performed to examine odds ratio (OR) of pregnancy outcomes. Three trajectories of GWG were identified in these 11,604 women with GDM. Trajectory 1: 64.02% of women had sustained moderate GWG throughout pregnancy; Trajectory 2: 17.75% of women showed a high initial GWG but followed by a low GWG from the third trimester until delivery; Trajectory 3: 18.23% had low initial GWG but followed by drastic GWG from the second trimester until delivery. Compared with pregnant women with Trajectory 1, women with Trajectory 2 had a higher risk of large for gestational age (adjusted odds ratio [AOR]: 1.29, 95% confidence interval [CI]: 1.12-1.48) but at a lower risk of having hypertensive disorders of pregnancy (AOR: 0.76, 95% CI: 0.57-0.96). Women in Trajectory 3 were more likely to develop small for gestational age (AOR: 2.12, 95% CI: 1.62-2.78), low birthweight (AOR: 1.49, 95% CI: 1.07-2.08), preterm birth (AOR: 1.28, 95% CI: 1.05-1.63), caesarean section (AOR: 1.26, 95% CI: 1.112-1.42) and hypertensive disorders of pregnancy (AOR: 2.24, 95% CI: 1.82-2.76). The association of GWG trajectory with adverse pregnancy outcomes differs across prepregnancy body mass index and GWG categories. Women with a slow initial GWG but followed by drastic GWG had higher risks of adverse pregnancy outcomes. Early clinical recognition of poor GWG trajectory will contribute to early intervention in high-risk groups to minimise adverse outcomes.