Infertility, << `ihn` fur TIHL uh tee, >> in human beings, is the inability of a man and a woman to produce children together. Both the man and the woman might be able to have children with other partners. For this reason, experts usually regard infertility as a condition of the couple rather than of either individual. Infertility may be temporary and treatable, or it may be permanent. Permanent infertility is called sterility. Experts also consider couples who have repeated miscarriages to be infertile.
Causes.
Infertility may result from abnormal development, abnormal function, or disease of the reproductive system. In some cases, the condition can be traced to one specific disorder in either the man or the woman. But much of the time, infertility results from a number of factors involving both partners.
Male infertility frequently occurs because of problems with sperm. In these cases, laboratory tests of sperm samples usually reveal an absence of sperm, a low sperm count, or a high percentage of abnormal sperm. Other causes of male infertility include infections and malfunctioning glands. Most commonly, however, doctors cannot determine a specific cause.
Many cases of female infertility involve blockage of a woman’s fallopian tubes, which transport eggs from the ovaries to the uterus. Fertilization of an egg by a sperm usually occurs in one of these two tubes. Blocked fallopian tubes prevent eggs from entering the uterus, where a fertilized egg develops into a fetus. Sexually transmitted diseases are the main cause of such blockage.
Two other causes of female infertility are anovulation and endometriosis (pronounced an oh vyuh LAY shuhn and ehn doh mee tree OH sihs). Anovulation is the failure of a woman’s ovaries to release eggs. This failure is caused by disorders involving endocrine glands, especially the ovaries, the hypothalamus, and the pituitary. Endometriosis is a disease that may harm the function of a woman’s ovaries and other reproductive organs.
Treatment.
In both men and women, surgery can often correct infertility caused by blockages or other structural disorders of the reproductive organs. For example, surgeons may open blocked fallopian tubes. Doctors treat infections of the reproductive system with antibiotics. Hormone treatment may correct infertility caused by malfunctioning glands.
Doctors prescribe drugs called fertility drugs to improve production of both sperm and eggs. In women, fertility drugs often stimulate production of more than one egg, which can result in a multiple pregnancy. Doctors can prevent multiple pregnancies by using ultrasound to monitor the ovaries. As soon as the first egg matures, the patient stops taking fertility drugs.
Infertility caused by sperm problems can be treated with a procedure called artificial insemination. In this procedure, a doctor places sperm from a woman’s partner or a donor directly into her reproductive system.
During the late 1900’s, experts developed a group of advanced infertility treatments called assisted reproductive technology (ART). Doctors perform ART procedures for patients with severe infertility that cannot be treated by other means. Examples of such patients are women with blocked fallopian tubes that cannot be opened surgically and men with extremely low sperm counts.
The most common ART technique is called in vitro << ihn VY troh or ihn VIHT roh >> fertilization, in which eggs and sperm are combined in a laboratory dish. If the unfertilized eggs and sperm are then placed into a woman’s fallopian tubes, the procedure is called gamete intrafallopian transfer (pronounced GAM eet ihn truh fuh LOH pee uhn TRANS fur, often shortened to GIFT). When fertilized eggs (also called zygotes) are placed in her fallopian tubes, the technique is called zygote intrafallopian transfer (pronounced ZY goht ihn truh fuh LOH pee uhn TRANS fur, often shortened to ZIFT).
Once fertilized eggs begin to divide, they become embryos. When dividing eggs are placed in a woman’s uterus, the procedure is called embryo transfer. When embryos are placed in her fallopian tubes, this procedure is known as tubal embryo transfer (TET). In some cases, embryos may be frozen for later use.
The eggs and sperm may come from the couple being treated or from donors. The woman who produces the eggs takes fertility drugs to make several eggs mature at once. Using several eggs increases the likelihood of successful pregnancy. When a man has an exceptionally low sperm count, doctors sometimes achieve fertilization by using tiny instruments to insert individual sperm into eggs. This delicate technique is called intracytoplasmic << `ihn` truh `sy` tuh PLAZ mihk >> sperm injection, often shortened to ICSI.
