What are congenital uterine anomalies?
Congenital uterine anomalies are malformations of the uterus that develop during embryonic life. Congenital uterine anomalies occur in less than 5% of all women, but have been noted in up to 25% of women who have had miscarriages and/or deliveries of premature babies. When a woman is in her mother’s womb, her uterus develops as two separate halves that fuse together before she is born. When a woman's uterus develops differently from most women, it is called a uterine anomaly.
What are the types of congenital uterine anomalies?
The types of congenital uterine anomalies include:
- Septate: a normal external uterine surface but two endometrial cavities
- Bicornuate: an abnormal, indented external uterine surface and two endometrial cavities
- Arcuate: a normal external uterine surface with a 1 cm or less indentation into the endometrial cavity
- Unicornuate: only one half of the uterus has developed
- Didelphys: the two halves of the uterus remain separate
The septate uterus and bicornuate uterus are the most common congenital uterine anomalies. The arcuate uterus is considered a variation of normal uterine development by most obstetricians and gynecologists.
What causes congenital uterine anomalies?
In the majority of cases, the cause of a congenital uterine anomaly is unknown. Most women with these malformations (more than 90%) have a normal number of chromosomes, 46 XX. Between 1938 and 1971, some pregnant women were treated with diethylstilbestrol (DES) to help prevent miscarriages and premature deliveries. Women who were exposed to DES while in their mother’s womb are at increased risk for having a congenital uterine anomaly. At this time, there are no well-established risk factors for the development of a congenital uterine anomaly, and there is no way to prevent development of a congenital uterine anomaly.
What are the symptoms of congenital uterine anomalies?
Although congenital uterine anomalies are present at birth, these malformations are usually without symptoms. Some women may have pain with their menstrual periods. Congenital uterine anomalies typically do not cause a woman to have difficulty getting pregnant. However, these malformations are often discovered during evaluations for infertility or pregnancy loss.
How are congenital uterine anomalies diagnosed?
A complete medical history and physical examination may cause an obstetrician or gynecologists to suspect that a congenital uterine anomaly is present. However, imaging studies, such as a hysterosalpingogram and ultrasound, or an MRI, are required to visualize the uterus and confirm that a congenital uterine anomaly is present.
How are congenital uterine anomalies treated?
There are no non-surgical treatments for congenital uterine anomalies. Recommendations for surgical treatment of congenital uterine anomalies depend on the particular anomaly and the woman’s reproductive history. If a septate uterus is diagnosed during an evaluation for infertility and/or pregnancy loss, surgical treatment is usually advised. Bicornuate, unicornuate and didelphic uteri rarely require surgical treatment.
Many women with a congenital uterine anomaly have no medical or reproductive problems. Congenital uterine anomalies may increase the likelihood that a woman will have a miscarriage or a premature delivery. If a woman has a septate uterus and has had miscarriages, surgical treatment will improve her chances for a successful pregnancy.