What causes infertility in men? Infertility in men can be caused by different factors and is typically evaluated by a semen analysis. A specialist will evaluate the number of sperm (concentration), motility (movement), and morphology (shape). A slightly abnormal semen analysis does not mean that a man is necessarily infertile. Instead, a semen analysis helps determine if and how male factors are contributing to infertility. Conditions that can contribute to abnormal semen analyses include - Varicoceles, a condition in which the veins on a man's testicles are large and cause them to overheat. The heat may affect the number or shape of the sperm. Medical conditions or exposures such as diabetes, cystic fibrosis, trauma, infection, testicular failure, or treatment with chemotherapy or radiation. Unhealthy habits such as heavy alcohol use, testosterone supplementation, smoking, anabolic steroid use, and illicit drug use. Environmental toxins including exposure to pesticides and lead. What causes infertility in women? Women need functioning ovaries, fallopian tubes, and a uterus to get pregnant. Conditions affecting any one of these organs can contribute to female infertility. Some of these conditions are listed below and can be evaluated using a number of different tests. Ovarian function (presence or absence of ovulation and effects of ovarian "age") Ovulation. Regular predictable periods that occur every 24–32 days likely reflect ovulation. Ovulation can be predicted by using an ovulation predictor kit and can be confirmed by a blood test to see the woman's progesterone level. A woman's menstrual cycle is, on average, 28 days long. Day 1 is defined as the first day of "full flow." A woman with irregular periods is likely not ovulating. This may be because of several conditions and warrants an evaluation by a doctor. Potential causes of anovulation include the following: Polycystic ovary syndrome (PCOS). PCOS is a hormone imbalance problem that can interfere with normal ovulation. PCOS is the most common cause of female infertility. Functional hypothalamic amenorrhea (FHA). FHA relates to excessive physical or emotional stress that results in amenorrhea (absent periods). Diminished ovarian reserve (DOR). This occurs when the ability of the ovary to produce eggs is reduced because of congenital, medical, surgical, or unexplained causes. Ovarian reserves naturally decline with age. Premature ovarian insufficiency (POI). POI occurs when a woman's ovaries fail before she is 40 years of age. It is similar to premature (early) menopause. Menopause. Menopause is an age-appropriate decline in ovarian function that usually occurs around age 50. It is often associated with hot-flashes and irregular periods. Ovarian function. Several tests exist to evaluate a woman's ovarian function. No single test is a perfect predictor of fertility. The most commonly used markers of ovarian function include follicle stimulating hormone (FSH) value on day 3–5 of the menstrual cycle, anti-mullerian hormone value (AMH), and antral follicle count (AFC) using a transvaginal ultrasound. Best Fertility Care Center, Advanced Fertility Care Center, State of Art Equipments, Ashwini Hospital Moondrumavadi Madurai -07 , Maternal and child health care .