Congenital Uterine Anomalies

Sometimes the cause of infertility can be attributed to congenital anomalies (birth defects) of the uterus, or those that occur after birth. Both congenital and acquired uterine abnormalities are significant causes of infertility, recurrent pregnancy loss and can create difficulties in carrying a pregnancy to term.

The doctors at Medfem Fertility Clinic are experts in the diagnosis and treatment of uterine anomalies. Through the use of advanced imaging techniques such as hysterosalpingograms (HSG) and transvaginal ultrasounds in reproductive-age women, our doctors are more easily able to detect the presence of uterine anomalies in patients.

Typically congenital abnormalities, present from birth and referred to as Mullerian anomalies, occur when the uterus is forming in the fetus. The uterus develops from a specialised type of tissue called Mullerian tissue. During embryonic development, a female fetus actually starts out with two small uteri – one near each kidney.  As the fetus develops, each uterus migrates down toward the tissue that ultimately becomes the vagina, and toward the middle of the patient’s body where it fuses with the uterus from the other side. Under normal circumstances, the wall where the two uteri join reabsorbs completely – from the bottom of the uterus to the top – resulting in a triangular shaped uterine cavity. Any alteration of this development can lead to a Mullerian anomaly.

The most common Mullerian anomalies include:

• Septate uterus: A septate uterus is where the inside of the uterus is divided by a muscular or fibrous wall (septum). The septum may extend only part way into the uterus (partial septate uterus) or it may reach as far as the cervix (complete septate uterus. About one woman in 45 women is affected (Chan et al 2011a).
• Bicornuate uterus: A bicornuate uterus (a womb with two ‘horns’) is the most common congenital uterine anomaly. Instead of the womb being pear-shaped, it is shaped like a heart, with a deep indentation at the top. It is called a uterus with two horns, because of its shape. This means that the baby has less space to grow than in a normally shaped womb. It’s thought that less than one woman in 200 women has a bicornuate uterus (Chan et al 2011a).
• Unicornuate uterus: A unicornuate uterus (a womb with one ‘horn’) happens when the tissue that forms the womb does not develop properly. This is a very rare condition affecting about one in 1,000 women. A unicornuate uterus is just half the size of a normal womb and the woman has only one fallopian tube. However, she usually has two ovaries, but usually only one will be connected to the uterus.
• Didelphic Uterus: This condition exists when a woman has two separate uterine bodies, each one with a cervix. Women with this malformation typically do not have substantially increased difficulty in getting pregnant, but they may be at a higher risk for preterm delivery, breech delivery, and miscarriage. It affects about one in 350 women.

About one in six women have a uterus that tilts backwards toward the spine which leads away from the bladder rather than over it (retroverted uterus). This is not an abnormality. It won’t affect how your baby grows, although it may mean your bump starts to show later than for other women, and it will not make you less fertile.

Among all congenital uterine abnormalities, the septate and bicornuate uterus are the most common and the most highly associated with reproductive failure and obstetrical complications, including first and second trimester miscarriage, preterm delivery, fetal malpresentation, intrauterine growth retardation, and infertility.

Diagnosis

A complete medical history and physical examination may lead us to suspect that a congenital uterine anomaly is present. However, imaging studies, such as a hysterosalpingogram (HSG) and ultrasound, or an MRI are required to visualise the uterus and confirm that a congenital uterine anomaly is present.

Treatment

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 or bicornuate uterus is diagnosed during an evaluation for infertility and/or pregnancy loss, surgical treatment is usually advised. No surgical procedure has been shown to be effective in the treatment of either unicornuate uterus or uterus didelphys.

Pregnancy can generally be attempted roughly three months after surgery, and the prognosis for a successful pregnancy is excellent. It is unlikely that your gynaecologist will allow you to proceed with a normal labour and may insist that a caesarean section be performed based on the increased risk of uterine rupture during labour.

Acquired Uterine Abnormalities

A variety of other uterine abnormalities can develop after birth.  These are referred to as “acquired abnormalities”. Examples include endometrial polyps, intrauterine adhesions, and uterine fibroids.

These conditions frequently cause symptoms – such as increasingly severe menstrual cramps, heavier or irregular vaginal bleeding, or changes in bowel or bladder function.  On some occasions, patients are unaware that they have these conditions and they are only discovered as part of a fertility evaluation.  Typically large fibroids can be detected during a pelvic examination, however smaller fibroids, fibroids within the uterine cavity, polyps, and adhesions can only be detected by some sort of imaging technique – either a sonogram, an HSG, or a sonohysterogram.

If you have been diagnosed with, or are suspected of having a uterine anomaly, the specialists at Medfem Fertility clinic are here to provide you with the necessary information to help you make informed treatment decisions.