Uterine Septum: Diagnosis and Treatment
As a fertility doctor, I frequently evaluate the uterus to identify any issues that could be preventing pregnancy or contributing to pregnancy loss. One common uterine abnormality I encounter is a condition called a uterine septum. In this blog post, I'll explain what a uterine septum is, how it's diagnosed, and what can be done about it.
Uterine Birth Defects
The uterus develops from two structures called the mullerian ducts, which start out as two little buds in the fetus. These ducts elongate, fuse together, and form the top third of the vagina, the cervix, the uterus, and the fallopian tubes. Normally, the midline connecting portion of the ducts reabsorbs, leaving a tubular structure. However, in some cases, there is a failure of this reabsorption, resulting in a remnant of tissue protruding into the uterine cavity. This is known as a uterine septum. Interestingly, because the mullerian ducts develop in close proximity to the kidneys, individuals with a uterine abnormality are also at higher risk of having a renal (kidney) abnormality. Uterine septums are just one type of uterine abnormality. Others include complete absence of the uterus (mullerian agenesis), a uterus with only one side formed (unicornuate uterus), two separate uterine cavities (uterine didelphys), and a heart-shaped uterus (bicornuate uterus). While these conditions can all impact fertility and pregnancy outcomes, septums are the most common, accounting for 35-40% of all uterine abnormalities. One key difference between a septate and bicornuate uterus is that with a septum, the outside of the uterus appears normal, while in a bicornuate uterus, the indentation on the outside is visible. This can make septums more difficult to diagnose without specialized imaging tests like saline sonograms, 3D ultrasounds, or MRI. The major concern with a uterine septum is the significantly higher risk of miscarriage. Studies show that 70-80% of pregnancies in women with a septum will end in miscarriage, compared to only 15-20% in women with a normal uterus. This is because the septum is an area of poor blood supply, making it difficult for a pregnancy to properly implant and thrive.
Septum Removal
The good news is that removing the septum, through a procedure called a hysteroscopic septum resection or metroplasty, can dramatically improve outcomes. After the septum is surgically removed, live birth rates increase substantially. The procedure is relatively low-risk, with a complication rate under 2%, but should be performed by an experienced reproductive endocrinologist or minimally invasive gynecologic surgeon. The recovery process typically takes about 8-10 weeks. First, the patient takes birth control pills to thin the uterine lining, making the septum easier to visualize and remove. The surgery is then performed, often with the placement of a balloon or stent to keep the uterine walls apart as they heal. Hormonal treatments with estrogen and antibiotics help prevent scar tissue formation. A follow-up saline sonogram is done to ensure complete septum removal and proper healing. It's important to note that many women with a uterine septum have no symptoms at all - no issues with their periods, tampons, or day-to-day life.
Diagnosis
The septum is often only discovered during an evaluation for infertility or recurrent pregnancy loss. This is why I recommend that anyone with a history of miscarriages or difficulty conceiving undergo a thorough uterine evaluation, even if previous ultrasounds appeared normal. In my opinion, if a uterine septum is identified, it should be addressed proactively before a pregnancy is attempted. The risk of miscarriage is simply too high to wait until after a failed pregnancy. Of course, this is a personal decision that should be made in consultation with your fertility specialist. Some may choose to try naturally first, but I believe the data on improved live birth rates after septum removal is compelling.
In summary, a uterine septum is a common uterine abnormality that significantly increases the risk of miscarriage. Fortunately, it can be diagnosed through specialized imaging and effectively treated with minimally invasive surgery.
