Understanding Infertility -- The Basics
Infertility means not getting pregnant after a year of regular, unprotected sex. The man, the woman, or both, may have a fertility problem. In women over 35 years old, infertility means not getting pregnant after six months of regular, unprotected sex.
Infertility doesn't always doesn't mean a person is sterile -- unable ever to have a child. Up to 15% of all couples are infertile, but only 1% to 2% are sterile. Half of couples who seek help can eventually have a child, either on their own or with medical help.
Both men and women can have a fertility problem. In about 20% of infertile couples, both partners have fertility problems, and in about 15% of couples, no cause is found after all tests have been done. This is called "unexplained infertility."
For many couples, infertility is a crisis. Fertility problems often come with feelings of guilt or inadequacy.
Couples trying to get pregnant should see a doctor as soon as they start trying to get pregnant -- especially if either or both partners have medical issues. During the visit, they can explore whether there are any problems that should be treated to improve fertility and raise their chances of getting pregnant and having a healthy baby.
What Causes Fertility Problems in Men?
In men, the most common reasons for infertility are problems with sperm, including:
- Low sperm count. Too few or no sperm in the semen.
- Low sperm motility. Sperm don't move as well as they should.
- Malformation of the sperm.
- Blocked sperm ducts.
Another common problem is a temporary drop in sperm production. This happens when the testicles have been injured, such as when they have been too hot for too long or the man has been exposed to chemicals or drugs that affect sperm production.
Drinking alcohol and smoking can lower sperm count. And men 40 and older have lower fertility.
What Causes Fertility Problems in Women?
The main reason for infertility in women is not ovulating, which means not releasing eggs from the ovary. Polycystic ovary syndrome (PCOS) is the main cause of not ovulating.
Problems with the fallopian tubes, which carry eggs from the ovary to the uterus, are a common cause of female infertility. Sometimes the tubes are blocked by scar tissue from an infection or from a condition called endometriosis.
If an egg does make its way thorough the fallopian tubes, many things can stop it from implanting in the uterus. And cervical mucus can damage sperm or slow their progress.
Age can be a problem, too. In women, fertility drops with age, and even more so after the age of 35. Getting pregnantafter age 45 is rare. Being overweight or underweight can also play a role.
WebMD Medical Reference

