Mean platelet counts vs gestation age. Changes in mean platelet count during the first, second, and third trimesters, at delivery, and during the postpartum period in pregnancies diagnosed with severe GT (n = 870), mild GT (n = 10 038), and controls (n = 82 523) from 2 hospitals. The smoothing function is the generalized additive model. The ribbon around the smooth curve denotes the 95% CI. The first trimester refers to the time from conception until 14 weeks (98 days) of pregnancy, the second trimester is from week 14 to the end of week 28 (196 days), and the third trimester is from week 28 to delivery. The mean gestation age at delivery in our study is ∼273 days. D, delivery; P, postpartum; PLT, platelet count.