What causes infertility in women?
- Ovulation is the release of the egg from the woman's ovary.
- It happens one time per month, about half way between one menstrual period and the next.
- Without normal ovulation, a woman can't get pregnant.
- A woman with ovulation problems may have periods that don't come on time each month. Or she may skip periods.
- Ovulation problems can be caused by hormone imbalances.
Blocked fallopian tubes.
- To get pregnant, a woman's egg must move from the ovary to the uterus (womb).
- The egg moves through the fallopian tube. The fallopian tube is where the egg and sperm meet (fertilization).
- If the fallopian tube gets blocked due to infection, surgery, or other problems, then sperm cannot reach the egg to fertilize it .
- The fertilized egg travels to the uterus (womb), attaches to the wall of the uterus, and pregnancy starts.
- If the shape of the uterus is not normal, the fertilized egg may not attach to the uterine wall, and the woman won't get pregnant.
- Fibroids are lumps of extra uterine muscle that can form on the inside of the uterus.
- Fibroids can make it hard for the fertilized egg to attach to the uterus.
What causes infertility in men?
- A varicocele happens when a vein on a man's testicles gets too large.
- The big veins heat the testicles.
- The heat damages the sperm.
Problems with sperm.
- If a man makes too few sperm or none at all the woman can't get pregnant.
- If the sperm don't move right they won't meet (fertilize) the egg.
- Sperm travel in tubes from the man's testicles to the penis.
- If the tubes are blocked, the sperm can't get out to fertilize the egg, the woman can't get prgnant.
What decreases the chance of getting pregnant?
- Age 30 or older (at age 40 there is a big drop in the chance of getting pregnant).
- Heavy alcohol use.
- Poor diet.
- Too much athletic training.
- Overweight or underweight.
- Sexually transmitted infections (STIs).
- Health problems that cause changes in the hormones in a woman's body.
- Age (over age 40 there are more fertility problems)
- Heavy alcohol use.
- Environmental toxins, including pesticides and lead.
- Health problems such as mumps or hormone problems.
- Radiation treatment and chemotherapy.
Are there tests for infertility?
In many cases, tests can help find the cause of infertility.
Tests for women and men:
- Physical exam.
- Questions about medical problems in the past.
Tests for women:
- Pelvic exam.
- Ovulation predictor tests.
- Imaging tests to check the shape of the uterus and fallopian tubes.
- Blood tests to check hormone levels.
- Laparoscopy (a procedure where a small needle is inserted into the abdomen (belly area) to check the fallopian tubes, ovaries and uterus).
- Basal body temperature charting (checking the temperature every morning to check for ovulation).
Tests for men:
- Semen analysis to check the number, shape, and movement of sperm.
Is there a way to increase the chance of getting pregnant?
- Having sex near the time of ovulation is the best way to increase the chance of getting pregnant.
- Ovulation occurs about 2 weeks before the next period starts.
- If a woman gets her period every 28 days, ovulation happens about 14 days after she starts her period.
- The couple should have sex at least every 3 days between the 10th and 18th day after the woman starts her period.
- They should make sure to have sex during the 3 days before ovulation.
National Center for Biotechnology Information, U.S. National Library of Medicine:
Centers for Disease Control and Prevention
U.S. Food and Drug Administration
- Infertility (pdf, 112 kb)