Most experts define infertility as not getting pregnant after at least one year of trying. Women who are able to get pregnant but then have repeat miscarriages are also considered to be infertile.
Pregnancy is the result of a complex chain of events. In order to get pregnant:
A woman must release an egg from one of her ovaries (ovulation)
The egg must go througha fallopian tube toward the uterus (womb).
A man's sperm must join with (fertilize) the egg along the way.
The fertilized egg must attach to the inside of the uterus (implantation).
Infertility can result from problems that interfere with any of these steps.
Infertility is not always a woman's issue. In only about one-third of cases is infertility due to the female factors. In another one third of cases, infertility is caused by the male factors. The remaining causes are either not established, or are caused by a mixture of male and female factors together.