Congenital malformations of female genitalia may be inherited or occur during abnormal embryonic development. They can cause infertility or complicate pregnancy. We refer to the rare congenital developmental defect of the genitalia (uterus septus communicans cum cervix duplex et vagina septa) which is compatible with high risk pregnancy. We demonstrate the importance of accurate description of the defect for monitoring and the successful course and timely adequate termination of pregnancy. Failure to recognize this defect could have fatal consequences, especially for the fetus.