"Infertility" is a term used to describe the inability of a woman or man to conceive a child or the inability of a woman to carry a pregnancy to term. Infertility is defined clinically in women and men who cannot achieve pregnancy after 1 year of having sex without using birth control and in women who have two or more failed pregnancies. In women older than age 35, the time frame is reduced to 6 months to indicate that earlier evaluation in this age group is appropriate, because fertility declines as a woman gets older. Many different medical conditions and other factors can contribute to fertility problems, and an individual case may have a single cause, several causes, or—in some cases—no identifiable cause. NICHD scientists and others supported by the Institute are conducting research to identify both the causes of infertility and new treatments that may allow more men and women to achieve pregnancy and, for women, to deliver a liveborn infant.

For more information about this topic, select the
Condition Information, Research Information, Clinical Trials, or Resources and Publications link in the menu on the left.
Common Names
- Infertility
- Fertility Problems
Medical or Scientific Name