Guest Author - Krissi Danielsson

The following is another installment in the Miscarriage Causes series. As always, remember that I am not a medical professional; this information is aggregated and summarized from online research and should not be interpreted as medical advice.

Evaluation for uterine anomalies is a pretty standard part of the recurrent miscarriage workup that most doctors will start after a woman's second loss. According to the University of Chicago, 12 to 15 percent of women with recurrent miscarriages have a uterine anomaly, but 70 to 80 percent of them can go on to carry a pregnancy after it is repaired.

Depending on the type of anomaly, these problems with the uterus can make it difficult or impossible for a fertilized egg to implant in a way that a baby can grow. Uterine anomalies may be caused by genetics or by past uterine injury.

The following are the most common types of uterine anomalies:

Septate Uterus

Sometimes called a "uterine septum," this means that your uterus shape has a partial divider extending into the open part of your uterus. In most cases, this "septum" has no blood vessels or at least very few. If a developing egg would implant on the septum, miscarriage would be a likely result -- usually by the end of the first trimester. Doctors can check for a septum by doing a hysterosalpingogram or hysteroscopy. In a hysteroscopy, which often involves general anesthesia, the doctor can go ahead and make repairs to the uterus while performing the test, if needed. The treatment for a septate uterus is surgical removal of the septum.

Bicornuate Uterus

A bicornuate uterus is heart shaped. Many women with a bicornuate uterus can carry a pregnancy without complications, but others seem prone to miscarriages. Treatment is generally the same as with a septate uterus, but a bicornuate uterus may require more extensive reconstruction.

Fibroids

Fibroids are growths in the uterine wall. They may cause no problems for pregnancy, or the placement might interfere with the ability of a placenta to grow in some women. A 2004 study found that fibroids increased the risk of miscarriage; more extensive research is currently underway.

Incompetent Cervix

This is one of those miscarriage terms I hate for its insensitivity. An "incompetent cervix" generally refers to when a woman's cervix is unable to support the baby and begins to dilate and shorten too early, causing the baby to be born before reaching viability -- usually in the early second trimester. An incompetent cervix could result from genetics or from past trauma to the cervix, such as a large number of D&C procedures. Doctors can treat the condition by prescribing bedrest and using a stitch to support the cervix.

Asherman's Syndrom

Asherman's Syndrome refers to scarring of the uterine wall, and it is a risk of having a D&C procedure or an infection in the uterus, although rare. Too much scarring can make it difficult for a placenta to develop properly, resulting in miscarriage. An experienced reproductive surgeon can repair some of this scarring in most cases. A symptom of Asherman's Syndrome would be a lack of a menstrual period or a change to unusually light periods after a D&C or infection.

Tests

The most common tests to look for the above anomalies are hysterosalpingogram (HSG) and hysteroscopy. Many doctors use HSG as the first round and hysteroscopy if the HSG shows evidence of a problem, but others go with hysteroscopy first since it has the benefit of being more accurate and providing the doctor with an opportunity to fix problems as they are diagnosed. Most of the above conditions are very treatable if detected.