Uterine Problems That Can Cause Infertility

A normal uterine cavity and endometrial lining are necessary conditions for conception as well as the maintenance of pregnancy for a full term. For many women struggling with infertility, they may have a uterine abnormality related to the cavity or the lining that may be incompatible with pregnancy.

When a woman has her monthly period, the endometrial lining of the uterus is shed. A new uterine lining is then regenerated over the next few weeks, eventually becoming receptive to a developing embryo. If implantation of the embryo does not occur, the balance of hormones would indicate that she is not pregnant. This leads to shedding of the uterine lining,and the regeneration process starts over.

Several pathologies of the uterus and the endometrial lining may be present, causing or contributing to problems with fertility as well as miscarriage.

1. Uterine myoma, leiomyoma: This is a benign neoplasm occurring in the smooth muscle layer of the uterus, which may cause anemia due to excessive menstrual bleeding, as well as infertility.

2. Uterine Polyps: Also known as endometrial polyps, these are masses found on the inner lining of the uterus. These can increase the risk of miscarriage among women undergoing in-vitro fertilization.

3. Congenital uterine malformations: Abnormally shaped uterine cavities, such as a bicornuate uterus, T-shaped uterus, or a uterine septum occur during embryogenesis and can interfere with implantation and are also incompatible with pregnancy. They can easily be detected via ultrasound, pelvic MRI or hysterosalpingography.

4. Intrauterine adhesions: After undergoing dilatation and curettage, typically after miscarriage or delivery, scar tissue and adhesions can form within the uterine cavity. Also known as Asherman’s Syndrome, these adhesions can interfere with implantation, leading to another miscarriage, infertility or other obstetric complications.

5. Luteal phase defect: This is a rare condition that where inadequate development of the microscopic and cellular changes in the endometrial lining of the uterus occurs after ovulation. The luteal phase is shorter than normal, and in many cases, the levels of the hormone progesterone are low.

6. Thin endometrial lining: An uncommoncondition, any lining less than 6mm in thickness can lead to miscarriage or failure to implant. A lining of at least 8mm is considered adequate for sustaining implantation and fetal development.During IVF treatment, the uterine lining starts at about 3mm thick at the end of the menstrual period. After estrogen levels rise sufficiently, the lining of the uterus thickens by about 1mm each day during IVF.