Objective: To examine whether women with a history of hysteroscopic adhesiolysis (HA)-treated intrauterine adhesions (IUAs) were at higher risk of adverse obstetrical outcomes in subsequent pregnancies. Design: Retrospective cohort study. Setting: A tertiary-care hospital in Shanghai, China. Population: 114,142 pregnant women who were issued an antenatal card and received routine antenatal care in Shanghai First Maternity and Infant Hospital between January 2016 and October 2021. Methods: From the cohort of 114,142 pregnant women, women with history of HA-treated IUAs before this pregnancy (N=780) were compared with 4 women with no history of IUAs (N=3010) matched on propensity score, maternal age and parity, mode of conception, pre-pregnancy BMI and prior history of abortion. Main outcome measures: Pregnancy complications, placental abnormalities, postpartum hemorrhage and adverse birth outcomes. Results : Compared with women with no history of IUAs, women with a history of HA-treated IUAs were at higher risks of preeclampsia (RR=1.69, 95% CI, 1.23, 2.33), placenta accreta spectrum (RR=4.72, 95% CI, 3.9, 5.73) and previa (RR=4.23, 95% CI, 2.85, 6.30), postpartum hemorrhage (RR=2.86, 95% CI, 1.94, 4.23), preterm premature rupture of membranes (RR=3.02, 95% CI, 1.97, 4.64) and iatrogenic preterm birth (RR=2.86, 95% CI, 2.14, 3.81) . Those women were also more likely to receive cervical cerclage (RR=5.63, 95% CI, 3.95, 8.02) during pregnancy and hemostatic therapies after delivery (RR=2.17, 95% CI, 1.75, 2.69). Moreover, we observed that the RRs of those adverse obstetrical outcomes increased with the increasing number of hysteroscopic surgeries. Conclusion: Our findings suggest that pregnant women with a history of HA-treated IUAs, especially those with a history of repeat HAs, are at higher risk of adverse obstetrical outcomes. Key words: hysteroscopic adhesiolysis, obstetrical outcomes, propensity score matching, cohort study