The impact of unicornuate uterus on perinatal outcomes after IVF/ICSI cycles: a matched retrospective cohort study

Objective: To evaluate the impact of unicornuate uterus on perinatal outcomes after in vitro fertilization and/or intracytoplasmic sperm injection (IVF/ICSI) cycles. Methods: We performed a retrospective cohort study including 160 women with unicornuate uterus and 1:1 matched controls with normally shaped uterus. They received IVF/ICSI treatment during January 2009 and December 2011. The perinatal outcomes were followed up till December 2014. Results: There were no significant differences in pregnancy rate, clinical pregnancy rate or live birth rate (53.6 versus 52.7, 41.4 versus 43.5, 33.8% versus 31.8%) between unicornuate uterus group and controls. Their biochemical pregnancy rate (22.8 versus 17.5%) and miscarriage rate (16.0 versus 18.8%) were similar. No significant differences were identified in preterm birth rate (18.3 versus 11.8%), birthweight (3.24 +/- 0.60 versus 3.33 +/- 0.54 kg) or birth length (50.47 +/- 2.33 versus 50.06 +/- 2.40 cm) among the singletons. However, lower gestational age (35.56 +/- 2.68 versus 36.71 +/- 1.73, p = .019), higher preterm birth rate (55.0 versus 34.4%, p = .038), lower birthweight (2.33 +/- 0.58 versus 2.69 +/- 0.38 kg, p = .001), lower birth length (45.33 +/- 2.46 versus 48.88 +/- 2.06 cm, p = .000), as well as higher rate of very low birthweight (13.2% versus 0, p = .007) were found for the twins from unicornuate uterus group. Conclusions: The results indicated unimpaired pregnancy and perinatal outcomes for women with unicornuate uterus conceiving one fetus. However, close attention should be paid to twin pregnancy in unicornuate uterus owing to increased risks of prematurity and low birthweight. Selected single embryo transfer is recommended for women with unicornuate uterus undergoing IVF/ICSI cycles.