Uterine septum is a deviation from normal shape of the uterus which is present congenitally (from birth). The uterine cavity is normal or slightly enlarged with a central septum. It is like a curtain dividing the uterine cavity into two spaces. This curtain can be partial i.e. dividing only the upper part of the cavity into two or complete, in which case the curtain divides the entire uterine cavity into two.
(Laparoscopic view of Arcuate uterus / uterus with septum)
3D Ultrasound image of T shaped uterus
USG image of T shaped uterus
T shaped uterus due to uterine septum
What is the cause of septum? The uterus is formed in a female fetus by fusion of two tubes. Incomplete central absorption of the tubes can lead to a septate uterus. Why the absorption should be incomplete is not known. Septate uterus can be hereditary but not always. It may be associated with congenital anomalies of kidney and ureters.
Around 3 % of women in reproductive age group will have septate uterus in some or another form. Around 15 % of women with history of recurrent abortion might have an underlying septate uterus.
What are the symptoms of septate uterus? In many a women septate uterus may never be diagnosed. They may even have history of normal pregnancy. Some of the women may have history of excessive bleeding during menses.
However it may lead to infertility and pregnancy loss. In a septate uterus, the septum or the curtain has less blood supply compared to the walls of uterus. If the embryo implants onto the septum, it may not grow due to poor blood supply and thus leading to failure of implantation. Infertility may be thus result of failure of implantation. In some cases the embryo may implant onto the septum, will grow to some extent, but then due to poor blood supply may lead to spontaneous (women may start bleeding soon after missed period) or missed (fetal heart activity may not be seen) abortion.
Abortion may also occur as the uterine cavity may not be big, enough due to the septum, for the embryo to grow. Even pregnancy losses between 3 to 6 months are common as congenital malformation of uterus is often associated with weak cervix (mouth of the uterus). This is however avoidable if USG is done to check the cervix. If any doubt of weak cervix is present on USG or the woman has past history of pregnancy loss after 3 months, a cervical stitch can be place to avoid any complications.
How is septate uterus diagnosed? It is most commonly diagnosed on Hysterosalpingography (HSG) or ultrasonography (USG).
In HSG either two cavities are seen or indentation onto the uterine fundus is visualized. A septum may be commonly diagnosed on USG as it is a routine investigation done for women with infertility or recurrent pregnancy loss.
Hysteroscopy is not a routine investigation to diagnose uterine septum but is used to treat the septum. Sometimes a small septum may be diagnosed during hysteroscopy, which can be treated in the same sitting.
MRI can also accurately diagnose a uterine septum. However other modalities are as sensitive in diagnosis and therefore it is not a cost-effective method for routine diagnosis of septate uterus.
Transvaginal USG showing evidence of septate uterus
MRI showing septate uterus
How is septate uterus treated? As such if the woman has no symptoms there is no need to treat septate uterus. Infertility and recurrent pregnancy loss are indications for treatment of septate uterus. Surgery is the only method for treatment for septate uterus. Medications cannot treat it.
Hysteroscopic visualization and resection is the gold standard of treatment.
Hysteroscopic septal resection or fundal metroplasty is the surgery which needs to be performed. In this a special knife mounted on resectoscope is used through which electric current is passed. This knife is used to cut the narrow walls of the uterine cavity and make the cavity broad. As the entire procedure is done under hysteroscopic guidance, it is very safe and equally effective.
A balloon may be kept in the uterine cavity to keep the cavity distended and to prevent scar formation for one week. Also some medications may be given for the lining to grow over the cut portion. Follow up may be scheduled after 7 days, when the balloon is removed. The growth of lining and response to surgery is monitored for the next month or more.
What are the complications of the surgery? The complications are same as in other operative hysteroscopy surgeries. However complication rates are negligible in hands of expert