Bicornuate uterus and birth defects

The uterus develops from two structures that normally join and remodel before a person is born. In a bicornuate uterus, joining is incomplete near the top, leaving a deep outer indentation and two upper spaces. The term congenital describes when this anatomy formed; it does not imply that it resulted from anything a parent did during pregnancy.

This uterine shape concerns the person carrying a pregnancy, not the baby's organs or chromosomes. It can change the amount and shape of space available as a pregnancy grows, which may influence fetal position or the course of pregnancy. Those pregnancy effects are different from a structural birth defect in the baby.

Before trying to conceive, bring any previous ultrasound, hysterosalpingogram, or MRI reports to a gynaecologist or obstetrician. Confirming the exact anatomy matters because a bicornuate uterus can be confused with other uterine shapes that have different management. Pelvic MRI can show both the cavity and the outer uterine contour when ultrasound has not provided enough detail.

During pregnancy, tell the maternity team about the diagnosis early. They can individualise ultrasound follow-up, review the baby's growth and position, assess the cervix when indicated, and discuss the likely route and timing of birth. Routine prenatal screening still addresses chromosomal and structural conditions in the baby; the uterine diagnosis does not replace those checks.

In pregnancy, obtain urgent medical advice for vaginal bleeding, leaking fluid, strong or regular contractions, severe abdominal or pelvic pain, fainting, fever, or a noticeable reduction in the baby's usual movements after movements have become established. These signs require assessment because of the symptom itself, regardless of uterine shape. Contact the maternity team if you are unsure where or how quickly to be seen.

You might ask how securely the diagnosis was established, whether your anatomy warrants additional imaging, how pregnancy monitoring will differ, and what symptoms should prompt a call to your maternity unit. If another congenital condition has been identified in you or your baby, ask whether separate testing or specialist counselling is appropriate for that finding.