Pregnancy outcomes in unicornuate uteri: a review.

OBJECTIVE: To elucidate the impact of unicornuate uteri on pregnancy outcomes as evidenced by historical and contemporary studies.

DESIGN: Publications related to unicornuate uterus were identified through MEDLINE and other bibliographic databases.

SETTING: Literature review in an academic research environment.

PATIENT(S): Premenopausal women with confirmed unicornuate uterus based on surgical or radiological evidence who were undergoing gynecologic and obstetrical care.

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): Rates of ectopic pregnancy, miscarriage, preterm delivery, intrauterine fetal demise, and live birth.

RESULT(S): Our review revealed 20 studies of varying size and design that had commented on pregnancy outcomes in unicornuate uteri. These studies ranged in date from 1953 to 2006 and from a sample size of one to 55 patients. In total, we examined 290 women with unicornuate uterus reported in the literature. Of those patients, 175 conceived, to carry a total of 468 pregnancies. Incidence data in the literature reveal that unicornuate uterus occurs in 1:4020 women in the general population; the anomaly, however, is significantly more common in infertile women, as in women with repeated poor outcomes. Our review revealed rates of 2.7% ectopic pregnancy, 24.3% first trimester abortion,9.7% second trimester abortion, 20.1% preterm delivery, 3.8% intrauterine fetal demise, and 51.5%live birth [corrected].

CONCLUSION(S): Unicornuate uterus is a Mullerian anomaly with prognostic implications for poorer outcomes during pregnancy. The rates of adverse outcomes have likely been historically overestimated. Although it is unclear whether interventions before conception or early in pregnancy such as resection of the rudimentary horn and prophylactic cervical cerclage decidedly improve obstetrical outcomes, current practice suggests that such interventions may be helpful. Women presenting with a history of this anomaly should be considered high-risk obstetrical patients.