For women - general factors that can affect the ability to ovulate, conceive, or deliver a child successfully include the following:

• age - women in their late 30s are generally less fertile than women in their early 20s

• endometriosis

• chronic diseases (diabetes, lupus, arthritis, hypertension, or asthma)

• hormonal imbalance

• environmental factors - cigarette smoking, alcohol consumption, or exposure to workplace hazards or toxins

• excessive or very low body fat

• abnormal Pap smears that have been treated with cryosurgery or cone biopsy

• DES taken by mother during pregnancy

• sexually transmitted diseases

• fallopian tube disease

• multiple miscarriages

For men - infertility is not just a woman's problem. Following is a list of risk factors related to male infertility:

• history of prostatitis, genital infection, or sexually transmitted diseases

• exposure to hazards on the job or toxic substances, such as radiation, radioactivity, welding, and many chemicals, including lead, ethylene dibromine, and vinyl chloride.

• cigarette or marijuana smoke

• heavy alcohol consumption

• exposure of the genitals to high temperatures

• hernia repair

• undescended testicles

• prescription drugs for ulcers or psoriasis

• DES taken by mother during pregnancy

• mumps after puberty