Objective: This study sought to determine whether second-trimester miscarriage was associated with an increased risk of recurrent second-trimester loss and spontaneous preterm birth in the second pregnancy of Chinese gestational women. Secondary objective was to examine whether different gestational weeks of second-trimester miscarriage had different effects on the second pregnancy outcomes. Study Design: A retrospective cohort study was undertaken in a lager, tertiary-referral university hospital (6500 deliveries per annum). Primiparous women with a second-trimester miscarriage (n=75), a spontaneous preterm birth (n=115), and a full term delivery (n=781)were identified from January 2015 to December 2017. Medical notes were reviewed and the number of complications among the three cohorts were identified. Results:1. Frequencies of subsequent second-trimester loss were 33.3%, 4.3%, and 1.2% in the second-trimester miscarriage, spontaneous preterm birth, and full-term delivery cohorts, respectively. Frequencies of subsequent spontaneous preterm birth were 24%, 38.3%, and 10.6% in the same 3 cohorts. Patients with a prior second-trimester miscarriage were 9.9 times more likely to have poor obstetric outcome, compared with those with prior full-term delivery(confidence interval 6.0 to 16.5, P﹤0.0001). 2.Women with cerclage have lower frequency of recurrent second-trimester loss and spontaneous PTB(P﹤0.05). 3.The frequency of poor obstetric outcome in women was 46% vs 65% vs 54% in those with index loss at less than 18weeks, 18+1-22weeks and longer than 22 weeks.(P =0.5)