Pregnancy Outcome of Infertile Patients with Uterine Malformation after Hysteroscopic and Laparoscopic Surgery

Background: Uterine malformations can be divided into the dysmorphic uterus (U1); septate uterus (U2); bicorporeal uterus (U3); hemiuterus (U4) and hypoplastic uterus (U5) with clinical significance ranging from mild to severe. This study aims to investigate whether different types of uterine malformations in infertile patients who have undergone hysteroscopic and laparoscopic surgery are associated with different pregnancy outcomes. Methods: This is a retrospective study of patients with uterine malformations and infertility admitted to the Department of Gynecology of Peking Union Medical College Hospital between January 2003 and December 2020. Patients were followed through 31 October 2021. Those lost to follow-up or who had not tried to become pregnant were excluded. Fertility outcomes included pregnancy rate, live birth rate and miscarriage rate. Fertility outcomes among patients experiencing different uterine anomalies were compared using one-way analysis of variance (ANOVA). Results: A total of 161 patients were included, of whom 62 (38.5%) had no other infertility-related factors except a uterine malformation. The rate of concomitant endometriosis (36.0%) was significantly higher than among the non-specific infertile population (p < 0.05). One hundred seventeen patients achieved a total of 151 pregnancies postoperatively. The total pregnancy rate was 77.5%, and the live birth rate was 73.4%. The pregnancy and miscarriage rates in patients with uterine septum with a single cervix were 76.0% and 15.5%, respectively; 75.0% and 37.5% among patients with unicornuate uterus with a single cervix; 88.9% and 9.5% among patients with uterine septum with a double cervix; 100% and 25% among patients with uterus duplex with double cervix; and 50% and 25% among patients with bicornuate uterus with a single cervix. Patients were grouped into either the septum group or the unicornuate uterus group dependent on the ability to enlarge the uterine cavity by surgery. The pregnancy rates for the two groups were 78.1% and 80.6%, respectively, with no significant difference noted (p = 0.599), although there was a significant difference in the miscarriage rate (14.4% vs. 33.3%) (p = 0.002). Conclusion: This retrospective analysis can help to illustrate differences in pregnancy outcomes of different types of uterine malformations although it lacked a proper control group. The non-obstructive uterine malformation may not be a dominant cause of infertility, and the volume of the uterine cavity may be a key factor leading to first-trimester miscarriage, rather than an important causative factor for infertility.