Abstract： Objective:To analyze the perinatal outcomes of unicornuate uterus pregnancy.Methods:The clinical data of patients with unicornuate uterus pregnancy who delivered between January 2009 and December 2018 in Women′s Hospital, School of Medicine, Zhejiang University, were reviewed retrospectively. Live birth was defined as the delivery of a baby after at least 28 weeks gestational age. Ninety-eight patients were diagnosed as unicornuate uterus, while 4 cases of stillbirth and 4 cases of twin pregnancy and 10 cases of incomplete data were excluded, and 80 patients with unicornuate uterus were included in the observation group. By matching the age, gestational age and delivery mode, 160 patients were randomly selected as the control group. The perinatal outcomes such as delivery mode, cesarean section indication sequence, postpartum hemorrhage, vaginal delivery time, newborn birth weight and Apgar score were analyzed retrospectively.Results:In the unicornuate uterus group, there were 10 cases of vaginal delivery and 70 cases of cesarean section, among which the primary indication of premature cesarean section and full-term cesarean section was abnormal fetal position, accounting for 7/18 and 50.0% (26/52), respectively. While in the control group, there were 20 cases of vagianl delivery and 140 cases of cesarean section, among which the main indications of premature cesarean section were placenta previa, intrahepatic cholestasis during pregnancy and scar uterus, accounting for 19.4% (7/36), and the primary indication of full-term cesarean section was abnormal fetal position, accounting for 23.1% (24/104). The postpartum hemorrhage of the vaginal delivery in the unicornuate uterus group and the control group was (319±161) and (261±152) ml, respectively, and the postpartum hemorrhage of the cesarean section delivery was (257±106) and (272±123) ml, respectively. There were no significant differences between the two groups statistically (all P>0.05). The time of the first stage of labor was (502±386) and (465±296) minutes in the unicornuate uterus group and the control group, and the time of the second stage was (74±73) and (47±30) minutes, respectively. There were no significant differences between the two groups statistically (all P>0.05). The neonatal birth weight in the unicornuate uterus group and the control group was (3 018±548) and (3 080±562) g, respectively, and there was no significant difference between the two groups statistically ( P=0.42). According to preterm birth and different pre-pregnancy body mass index, the neonatal birth weight of the two groups were compared, and the differences were not statistically significant (all P>0.05). One-minute Apgar score of premature in the unicornuate uterus group and the control group were 10 (9.25-10) and 10 (10-10), 5-minute Apgar score were 10 (10-10) and 10 (10-10), respectively. One-minute Apgar score of full-term in the unicornuate uterus group and the control group were 10 (10-10) and 10 (10-10), 5-minute Apgar score were 10 (10-10) and 10 (10-10), respectively. There were no statistically significant differences between the two groups, respectively (all P>0.05). Conclusions:The patients with unicornuate uterus could give birth vaginally in the absence of other operation indications. The perinatal outcome of women with unicornuate uterus is similar to that of women with non-uterine abnormalities. It is found that the abnormal fetal position with unicornuate uterus is the main reason for cesarean section.