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 about 30 percent 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 prostatis or genital infection
• exposure to toxic substances or hazards on the job, such as lead, cadmium, mercury, ethylene oxide, vinyl chloride, radioactivity, and x-rays
• 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