Understanding Infertility -- the Basics

Are you trying to have a baby but pregnancy just isn't happening? You may wonder if you or your partner has a medical problem that you need to check out. Take a few minutes to learn what infertility means and what can cause it. Then talk to your doctor to find out what your next steps should be.

Doctors call it infertility when you don't get pregnant after a year of regular sex without using birth control.  If you're a woman over 35, infertility means you don't get pregnant after 6 months of sex.

Infertility doesn't always mean you're "sterile" -- unable ever to have a child. Half of couples who seek help can eventually have a child, either on their own or with medical help.

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.

What Causes Fertility Problems in Men?

If you're a guy, the most common reason for infertility is a problem with sperm, including things like:

  • Low sperm count, which means you have too few or no sperm in your semen.
  • Your sperm don't move as well as they should, which is called low sperm motility.
  • You have abnormally formed sperm.
  • Your sperm ducts are blocked.

Another common problem is a temporary drop in the amount of sperm you make. This might happen when your testicles get injured. For instance, it could be that your testicles were too hot for too long, or you were in contact with chemicals or took drugs that affect the way you make sperm.

If you drink alcohol or smoke, your sperm count can go down.

Also, men 40 and older have lower fertility.

What Causes Fertility Problems in Women?

The main reason for infertility is that you don't ovulate, which means you don't release an egg from an ovary. A condition called polycystic ovary syndrome is the main cause.

Problems with your fallopian tubes, which carry eggs from the ovary to the uterus, are a common cause of infertility. Sometimes your tubes are blocked by scar tissue from an infection or from a condition called endometriosis.

Smoking can lead to fertility problems in women, and being overweight or underweight can also play a role.

If an egg does make its way through your fallopian tubes, many things can stop it from implanting in your uterus. And cervical mucus can damage sperm or slow their progress.

In women, fertility drops with age, and even more so after age 35. Getting pregnant after age 45 is rare.

WebMD Medical Reference Reviewed by Kecia Gaither, MD, MPH on June 23, 2016

Sources

SOURCES: 

International Council on Infertility Information and Dissemination.  

The Merck Manual 2005.

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