Figure 13 shows the primary diagnoses reported for infertility among couples who had an ART procedure in 1998. Although some couples have more than one cause of infertility, only one is reported as primary. In addition, diagnostic procedures and categories may vary from one clinic to another, so the categorization may be inexact. Tubal factor usually means that the woman s fallopian tubes are blocked or damaged, making it difficult for the egg to be fertilized or for an embryo to travel to the uterus. Male factor usually refers to a low sperm count or problems with sperm function that make it difficult for a sperm to fertilize an egg under normal conditions.
Endometriosis involves the presence of tissue similar to the uterine lining in abnormal locations.
This condition can affect both fertilization of the egg and embryo implantation. Ovulatory dysfunction means that the ovaries are not producing eggs normally or that egg production has diminished with age. Uterine factor means a disorder of the uterus that results in reduced fertility. Unexplained cause means that no cause of infertility was found in either the woman or the man. Other causes of infertility include immunological problems, chromosomal abnormalities, cancer chemotherapy, and serious illnesses.