Background: Uterine malformations can be divided into the dysmorphic
uterus (U1); septate uterus (U2); bicorporeal uterus (U3); hemi-uterus (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.