Congenital anomalies, or variations in reproductive anatomy, occur during fetal development and can affect the structure of the uterus. Among these variations, the septate uterus is the most commonly encountered type, representing over half of all uterine malformations. Understanding the specific nature of a septate uterus is important for people experiencing certain pregnancy complications or difficulties with conception.
Defining the Septate Uterus
A septate uterus is a congenital condition where a wall of tissue, known as a septum, divides the uterine cavity into two smaller spaces instead of a single, unified chamber. The septum’s size can range from a small ridge at the top of the uterus to a complete division that extends down to the cervix, creating a complete septate uterus.
This anomaly arises from an issue during the female fetus’s development. The uterus forms from the fusion of two structures called the Müllerian ducts; normally, the central wall between these ducts is fully reabsorbed. A septate uterus results when this resorption process is incomplete, leaving a dividing partition. The external shape of a septate uterus generally remains normal, resembling an upside-down pear, which distinguishes it from a bicornuate uterus that has a visibly heart-shaped exterior with a deep indentation at the top.
Recognizing the Signs and Diagnosis
Many women with this condition do not experience any noticeable symptoms and may not realize they have it until they encounter reproductive issues. The most common indicators that prompt investigation are recurrent pregnancy losses or, less frequently, unexplained infertility. Occasionally, a woman may experience painful menstruation, known as dysmenorrhea, or persistent pelvic discomfort.
Accurate diagnosis relies on imaging techniques that can clearly visualize the internal uterine structure and distinguish the septum from other anomalies. A three-dimensional (3D) transvaginal ultrasound is often the preferred initial non-invasive method. Magnetic Resonance Imaging (MRI) offers highly detailed cross-sectional images of the pelvic organs, providing a definitive view of the septum’s composition and the uterus’s external contour. Hysteroscopy, which involves inserting a small camera through the cervix, allows for direct visualization of the uterine cavity and is often used for confirmation and simultaneous treatment.
Impact on Pregnancy and Fertility
While a septate uterus does not typically affect a woman’s ability to conceive, it significantly increases the risk of adverse pregnancy outcomes. The primary problem lies in the septum’s poor blood supply. If an embryo implants onto this poorly vascularized septum, the placenta may not develop properly, leading to a high risk of recurrent first and second-trimester miscarriage.
For pregnancies that successfully implant outside of the septum and progress, other risks become a concern due to the compromised size and shape of the functional uterine cavity. The limited space can lead to a higher incidence of preterm labor and delivery. Furthermore, the baby may not be able to turn into the head-down position, resulting in fetal malpresentation, such as a breech position. This often necessitates a Cesarean delivery for a safe birth.
Corrective Procedures
For women who have experienced recurrent miscarriages or pregnancy complications attributed to a septate uterus, the condition can be surgically corrected to improve reproductive chances. The standard treatment is a minimally invasive procedure called hysteroscopic metroplasty, also known as septum resection. Specialized instruments are inserted through the vagina and cervix, guided by a hysteroscope, to carefully cut and remove the septum.
This technique restores the uterine cavity to a normal, unified shape without the need for abdominal incisions. Removing the dividing wall significantly reduces the risk of miscarriage by eliminating the area of poor blood supply and expanding the functional uterine space. Studies have shown that hysteroscopic metroplasty can lead to a substantial improvement in live birth rates for women who have suffered from recurrent pregnancy loss.