Congenital anomalies in the offspring of mothers with a bicornuate uterus.

BACKGROUND Most of the reports on mothers with bicornuate uterus analyze fertility, reproductive capacity, and pregnancy outcomes. Very few of them, however, mention the risk for congenital anomalies in their offspring. Further, to our knowledge, no epidemiologic studies estimating the risk for congenital defects and analyzing the type of anomalies observed in infants born to mothers with bicornuate uterus have been reported. METHODS Using a case-control study series, we estimated the risk of congenital anomalies in the offspring of women with a bicornuate uterus. To identify the specific defects associated with the presence of a bicornuate uterus in the mother, we analyzed 26 945 consecutive malformed infants from the Spanish Collaborative Study of Congenital Malformations and assessed the frequency of congenital anomalies in the offspring of mothers with a bicornuate uterus and in those born to mothers with a normal uterus. We then calculated the relative frequency, which is the quotient of the frequency of the individual defects in each group. This figure expresses the times each congenital defect is more frequent in infants of mothers with a bicornuate uterus than in those born to mothers with a normal uterus. RESULTS Offspring of mothers with a bicornuate uterus had a risk for congenital defects four times higher than infants born to women with a normal uterus. The risk was statistically significant for some specific defects such as nasal hypoplasia, omphalocele, limb deficiencies, teratomas, and acardia-anencephaly. CONCLUSIONS Offspring of mothers with bicornuate uterus are not only at high risk for deformations and disruptions, but also for some type of malformations.