Perinatal outcomes of twin pregnancies in women with a unicornuate uterus.

OBJECTIVE

A unicornuate uterus is a type of Müllerian anomaly and is associated with adverse pregnancy outcomes. However, the perinatal outcomes of twin pregnancies in women with a unicornuate uterus remain unknown, and previous studies on women with a unicornuate uterus have focused mostly on those with singleton pregnancies. This research aimed to investigate the perinatal outcomes of twin pregnancies in women with a unicornuate uterus.

METHODS

From January 2013 to December 2022, 283 women with a unicornuate uterus, including 21 with twin pregnancies (Group A), 262 with singleton pregnancies (Group B), and 105 with twin pregnancies and a normal uterus (Group C) were enrolled in this study and gave birth at West China Second University Hospital, Sichuan University. General characteristics and perinatal outcomes were retrospectively analysed using SPSS version 22.0.

RESULTS

Among the 21 women with twin pregnancies and a unicornuate uterus, 20 (95.2%) had dichorionic diamniotic twins, and 1 (4.8%) had monochorionic diamniotic twins. Seventeen patients (81.0%) conceived by in vitro fertilization-embryo transfer (IVF-ET), and 4 patients (19.0%) conceived naturally. The mean gestational age at delivery was 33.8 ± 5.7 weeks, and 19 patients (90.5%) underwent caesarean section. The twin group (A) had significantly higher rates of preterm premature rupture of membranes (38.1%, 8/21), preterm delivery (85.7%, 18/21) (preterm delivery was defined as a birth occurring after 28 weeks and before 37 completed weeks of gestation), and neonatal intensive care unit (64.3%, 27/42) admission than Groups B and C (p < 0.05). Moreover, the live birth weight in Group A (1931.7 ± 535.2 g) was lower than that in Groups B and C (p < 0.001).

CONCLUSION

The incidence of complications and the risk of adverse perinatal outcomes in women with twin pregnancies and a unicornuate uterus are greater than those in women with singleton pregnancies and a unicornuate uterus and women with twin pregnancies and a normal uterus. Thus, maternal and foetal monitoring during pregnancy should be strengthened to achieve good outcomes.