Trajectories of depressive symptoms during pregnancy and risk of premature birth: A multicenter and prospective cohort study

•The depressive symptoms of pregnant women during pregnancy were not constant, there are five distinct trajectories of depressive symptoms (Edinburgh Postpartum Depression Scale [EPDS] scores) from first to third trimester: low-stable, moderate-stable, moderate-rising, high-falling, high-stable.•The risk of premature birth (PTB) varied by trajectories of depressive symptoms, with the highest risk in the high-stable trajectory.•The associations between the trajectories of depressive symptoms and PTB were most significant in multiparous women with prior PTB, then in primiparous women, and finally in multiparous women without prior PTB.•There was no difference in the risk of early-moderate PTB among different trajectories of depressive symptoms and only the risk of late PTB was different among different trajectories.