Infertility Medical Conditions Affecting the Uterus
EndometriosisEndometriosis can be defined as the abnormal growth of endometrial cells (the cells that line the uterus and are shed monthly) outside the uterus. These cells can grow virtually anywhere, including the ovaries, the fallopian tubes, the intestines, within the pelvic cavity, in the vagina, the bladder, within old surgery scars…there is almost no limit to where these “implants” can be found. Endometriosis has even been found in women’s lungs and brains. Endometriosis is benign (not cancerous). Endometriosis affects women in their childbearing years, and it has been estimated that between 20 and 50% of women who are infertile have endometriosis. Endometriosis can affect fertility by causing scarring of structures necessary for pregnancy, such as the ovaries and fallopian tubes. It is also thought that endometriosis can negatively affect hormone levels, ovulation, and implantation of the embryo within the uterus. Researches claim that approximately 25% of infertility problems can be blamed on improperly functioning or blocked fallopian tubes.
Other Problems Affecting the Uterus
There are other conditions that can affect the uterus in addition to endometriosis:
- Uterine fibroids- fibroids are benign tumors that grow within the uterus or the uterine walls. They may range in size from tiny to very large, filling the entire uterus. A large fibroid may interfere with an embryo’s ability to implant in the uterus.
- Polyps- polyps develop from the uterine wall and protrude into the uterus. Polyps can also cause implantation problems and sometimes miscarriage when an embryo succeeds in implanting.
- Adenomyosis- adenomyosis occurs when the lining of the uterus migrates into the outer, muscular wall of the uterus. As a normal uterus shape and lining is needed for implantation, adenomyosis can also interfere with the ability to conceive.
- Septate/bicornuate uterus- sometimes congenital abnormalities of the uterus, such as a septate uterus, occur. In a septate uterus, the uterine cavity is Y-shaped, essentially divided into a right and left side. In a bicornuate uterus, there is a septum (divider) which cuts the uterus into two segments. Either of these conditions can cause infertility.
Infertility Medical Conditions Affecting the Fallopian TubesApproximately 25% of infertility problems can be blamed on improperly functioning or blocked fallopian tubes. The fallopian tubes are small and delicate, making them easily susceptible to damage and scarring, resulting in blockage. There are five main types of problems that can affect a woman’s fallopian tubes:
Infection- sexually transmitted diseases (STDs) can cause inflammation and scarring of the tubes. Sometimes infections not caused by sexual activity can occur. Whether STDs are the cause, or another bacteria or virus, the result is often the same- damage to the fallopian tubes. Unfortunately, many infections do not cause symptoms (i.e. chlamydia), or cause symptoms only after damage has been done.
Diseases of the abdomen- colitis (inflammation of the colon) and appendicitis are two common abdominal conditions that can lead to scarring and subsequent blockage of fallopian tubes.
Adhesions- scar formation is common after surgery; sometimes, abdominal surgery can cause scar tissue that can adhere to the fallopian tubes or change their shape, making it impossible for the egg to travel through the fallopian tubes. Some women are more prone to scar tissue formation than others.
Ectopic pregnancy- occasionally, embryos will implant in a fallopian tube instead of the uterus. As the embryo grows, it eventually outgrows the tube, which can cause irreparable damage to the fallopian tube and can even threaten the life of the mother. Ectopic pregnancies frequently result in the loss of the affected fallopian tube (and the pregnancy).
Congenital problems- sometimes the fallopian tubes are abnormally sized or shaped owing to a congenital defect. Tubal and uterine congenital defects often occur together.
Infertility Medical Conditions Resulting from Ovulation ProblemsProblems of ovulation are estimated to account for approximately 1/3 of women’s infertility. Ovulation is a complex process, and problems can occur at any point.
Ovulation requires a complex interplay among several hormones produced or affected by different areas of the body. A disruption in one hormone level will ultimately have an effect on ovulation.
- Failure to produce mature eggs- when the ovaries fail to produce mature eggs, fertilization cannot take place. Polycystic ovarian syndrome (PCOS) is a common condition resulting in anovulation, as well as a host of other symptoms. At the heart of the problem is a hormonal imbalance. In order for the ovaries to produce mature eggs, hormones must be balanced. Any condition which adversely affects this balance will affect fertility negatively.
- The hypothalamus- the hypothalamus, located in the brain, sends signals to the pituitary gland, which signals the ovaries to initiate maturation of the eggs. When the hypothalamus fails in its duty, the result is immature eggs.
- The pituitary gland- the pituitary (sometimes called the “master gland”) is responsible for producing and secreting the hormones FSH (follicle stimulating hormone) and LH (luteinizing hormone), which tell the ovaries to begin the process of egg maturation. When there is too little or too much of these hormones produced or secreted, eggs will fail to mature.
Miscellaneous ovarian problems
- Damage to the ovaries- scar tissue from previous abdominal or pelvic surgeries, ovarian cysts requiring surgical treatment or infections can all damage delicate ovaries so that follicles are unable to mature and release eggs. Endometriosis can also damage ovaries, leading to infertility.
- Follicular problems- in a few women, the follicles mature with an egg inside them, yet fail to rupture and release the egg. The egg is not released and ovulation cannot occur.