Reproductive performance in the next pregnancy for nulliparous women with history of first trimester spontaneous abortion

To determine whether interpregnancy interval after the first spontaneous abortion has an effect on reproductive performance of women in their next pregnancy. A prospective cohort study was conducted on 4,619 women with history of spontaneous abortion in their first pregnancy. Of them 2,422 (52.4 \%) conceived within 6 months of the miscarriage (group A) and 2,197 47.6 \% after 12 months (group B). The primary outcome was abortion, live birth, termination, or ectopic pregnancy in the next pregnancy. Secondary outcomes were preterm delivery, low birth weight infants, caesarean section rate and occurrence of preeclampsia, placental abruption and induced labour in the second pregnancy. Women who conceived again within 6 months were less likely to have another abortion, termination, or ectopic pregnancy compared with women with interpregnancy interval more than 12 months. Women with an interpregnancy interval more than 12 months were less likely to have live birth in the second pregnancy and more likely to have a caesarean section, preterm delivery, or infant of low birth weight compared with women who conceived again within 6 months. Women who conceive within 6 months after their first spontaneous abortion have better reproductive outcomes and the lowest complication rates in their subsequent pregnancy.