Some patients who struggle with infertility and recurrent pregnancy loss have an abnormal shaped uterus. A uterus can be misshaped due to 2 reasons: congenital (born with it) or acquired (born with a normal shape but developed an abnormality or had uterine surgery that changed the conformation of the uterus). Today, I discuss the most common type of congenitally misshaped uterus called the septate uterus.
The uterus (or womb) is a major female sex organ within which the fetus develops during pregnancy. When the “house” of the baby is abnormally shaped, both infertility and recurrent pregnancy loss may result. The uterus begins to form when the female is a fetus. The uterus is fully formed by the 22nd week of gestation. Congenital uterine anomalies occur in 5% of all women but can be as high as 2-3% in fertile women, 3% in infertile women, and 5-10% in women with recurrent miscarriages.
The most common uterine abnormality that women can be born with is a uterus with a septum in the middle (septate uterus). A septum is a partition separating two chambers. In other words, it is a wall that divides a space into 2 areas. An example I use to explain to my patients is the nasal septum. The nasal septum is a wall that separates the nasal airways into 2 chambers.
The uterine septum occurs when there is lack of absorption of the septum during the formation of the uterus. The body is supposed to remove the wall that naturally is present in the uterus during gestation. However, sometimes, the septum doesn’t get removed/absorbed and the wall remains within the uterus. A cause for the lack of absorption of the septum is unknown at this time.
A range of absorptions can occur leading to a spectrum of presentations. A partial absorption of the septum can result in abnormalities ranging from a slight midline septum to a significant midline division of the uterine cavity. A total failure in resorption could leave not only a complete midline division of the uterine cavity but also a longitudinal vaginal septum (a double vagina). Partial septate uteri are more common than complete.
A septate uterus does not lead to infertility. It leads to recurrent pregnancy losses. The greater the septum the greater the risk of recurrent miscarriages. Fortunately, a septum from a septate uterus can be removed surgically and can return the uterus (especially the interior of the uterus) to a normal shape. Hysteroscopy with septum resection is the surgery employed by Infertility specialists to remove a uterine septum.
Outcomes following removal of the septum are excellent. Miscarriage rates go from 90% prior to removal of the septum to 10% after removal.
If you have been found to have a uterine septum, ask your doctor about the treatments required.
Source: Speroff L, Glass R, Kase N, Clinical Gynecologic Endocrinology and Infertility , 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2005: 123-153.
Dr. Lowell Ku, M.D. is an award winning and leading Reproductive Endocrinology and Infertility specialist at Dallas IVF, one the nation’s premiere infertility centers. Dr. Ku clarifies the many confusing terms used in the world of Infertility using straightforward explanations.
