For one out of six couples in the United States, trying for parenthood is not a time of carefree joy, but one of increasing worry and despair, as pregnancy remains elusive. Physicians define infertility as the inability to conceive after a year of trying. A physical cause of the problem is found in 90% of cases, and 60% of the time, the abnormality lies in the female's reproductive system.

One of the more common causes of female infertility is hyposecretion of gonadotropic hormones, from the anterior pituitary gland, followed by failure to ovulate (anovulation). This type of anovulatory cycle can sometimes be detected by testing the female's urine for the presence of pregnanediol, a product of progesterone metabolism. Since the concentration of progesterone normally rises following ovulation, no increase in pregnanediol in the urine during the latter part of the menstrual cycle suggests lack of ovulation.

Fertility specialists can treat absence of ovulation due to too little secretion of gonadotropic hormones by administering hCG (obtained from human placentas) or another ovulation-stimulating biochemical, human menopausal gonadotropin (hMG), which contains LH and FSH and is obtained from urine of women who are past menopause. However, either hCG or hMG may overstimulate the ovaries and cause many follicles to release egg cells simultaneously, resulting in multiple births later.

Another cause of female infertility is endometriosis, in which tissue resembling the inner lining of the uterus (endometrium) is present abnormally in the abdominal cavity. Small pieces of the endometrium may move up through the uterine tubes during menses and implant in the abdominal cavity. Here it undergoes changes similar to those that take place in the uterine lining during the menstrual cycle. However, when the tissue begins to break down at the end of the cycle, it cannot be expelled to the outside. Instead, its products remain in the abdominal cavity where they may irritate its lining (peritoneum) and cause considerable abdominal pain. These products also tend to stimulate formation of fibrous tissue (fibrosis), which, in turn, may encase the ovary, preventing ovulation or may obstruct the uterine tubes.

Some women become infertile as a result of infections, such as gonorrhea, which may inflame and obstruct the uterine tubes, or may stimulate production of viscous mucus that can plug the cervix and prevent entry of sperm.

The first step in finding the right treatment for a particular patient is to determine the cause of the infertility.

Copyright ©1998 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use and Privacy Policy.
McGraw-Hill Higher Education is one of the many fine businesses of The McGraw-Hill Companies.
For further information about this site contact mhhe_webmaster@mcgraw-hill.com.