Infertility is defined as the inability to become pregnant, despite having frequent, unprotected sex for at least a year (or six months under certain circumstances). Infertility may also refer to the state of a woman not being able to carry a pregnancy to full term (resulting in miscarriage). About 10-15% of couples are infertile in the United States. Infertility may be due to a single cause in either you or your partner or a combination of factors. About one third of the time the cause of infertility only involves the male. About one third of the time, the cause of infertility only involves the female. In the remaining one third of the time, the cause involves both male and female or no cause can be found. The causes of male infertility include abnormal sperm production or function, problems with the delivery of sperm, overexposure to certain environmental factors, or damage related to cancer. Causes of female infertility include ovulation disorders, uterine or cervical abnormalities, fallopian tube damage or blockage, endometriosis, pelvic adhesions, thyroid problems, cancer treatment, or other conditions or medications. Risk factors for male and female infertility include advanced age (for women over 35, for men over 40), tobacco use, alcohol use, being overweight or underweight, not enough exercise, or too much strenuous, intense exercise (particularly for women). Diagnosis is made through a number of different tests. Testing and trial treatments may extend over several months. The good news is that there are many safe and effective therapies for overcoming infertility. And due to research, treatment options continue to improve the chances a couple will become pregnant. Talk with your obstetrician or midwife if you are having trouble becoming pregnant. He or she will most likely suggest you see an infertility specialist possibly at an infertility center. Support organizations are also good resources for support and information.