Infertility can be due to either male or female issues, but according to the Mayo Clinic, 30 to 40 percent of infertility cases are caused by both male and female issues. The most common reasons for having trouble conceiving are problems with ovulation (releasing a mature egg) and fertilization.
Poor Health
Your general health can either support or sabotage your fertility. The Mayo Clinic lists medications, cancer treatments such as aschemotherapy and radiation therapy, and medical disorders such as thyroid disorders, Cushing's disease, sickle cell disease, kidney disease and diabetes as possible factors that may decrease your fertility. Other lifestyle issues such as smoking, drug use and poor nutrition resulting in obesity or anorexia can also sabotage your attempts to get pregnant.
Blocked Tubes and Endometriosis
Fallopian tubes are where sperm and egg meet up and where fertilization happens. If your tubes are blocked or scarred shut, fertilization is impossible through intercourse or artificial insemination. Fallopian tubes can become scarred as a side effect of pelvic infections (pelvic inflammatory disease) caused by sexually transmitted diseases. Endometriosis, another common female cause of infertility, occurs when cells that normally line the uterus grow abnormally in or over reproductive organs in the pelvis, causing bleeding, scarring and inflammation that can prevent fertilization and pregnancy.
Irregular Periods
According to the American Pregnancy Association, diseases of the ovary involving hormonal disturbances such as Polycystic Ovarian Syndrome (PCOS) are a common cause of female infertility. Hormonal imbalance can cause irregular periods and you may not be releasing eggs from your ovaries (ovulating) every month. If you aren't ovulating normally, you are likely to have trouble conceiving.
Sperm Problems
According to the Mayo Clinic, 20 percent of infertility in couples are due only to male problems. If you are having problems conceiving, your partner should have a semen analysis to detect male factors such as low sperm count or abnormalities in the shape or function of sperm that can prevent fertilization.
Advanced Maternal Age
According to the National Institute of Health statistics, a woman's fertility starts to decline in her thirties and most women can expect to have reduced fertility simply due to the normal process of aging. The American Society for Reproductive Medicine recommends that women under the age of 35 allow themselves 12 months of trying to conceive before they seek infertility diagnosis and treatment. Older women may want to seek medical advice after 6 months of trying to conceive.
