Infertility is defined as the inability to become pregnant after one year of unprotected intercourse. It is a common medical condition, affecting about 15 percent of couples in the United States.

About 40 percent of cases are a result of female infertility. Twenty to 30 percent of cases are due to male infertility. In 15 to 20 percent of cases, no underlying cause can be identified.

Infertility may occur as a result of several disease states, many of which are influenced by diet and exercise. Couples that follow healthful diets, exercise, and maintain healthy weights are less likely to experience medical problems that impair fertility.

Risk Factors

• Smoking
• Infection of the reproductive tract
• Varicocele (swelling of the veins of the testicles)
• Endometriosis consumers/gynecology/endometriosis.html
  
• Polycystic ovarian syndrome
• Fibroids
• Celiac disease

Infertility: Diagnosis and Treatment

Diagnosis

• The evaluation begins with a medical history and a physical examination.
• Blood testing and genetic testing may be useful in some cases.
• In men, a semen analysis is done to measure the sperm count. In some cases, further testing may be necessary, including ultrasound or biopsy of the testicles.
• In women, testing to assess sex hormone concentrations and the sufficiency of ovulation may be necessary. In some cases, further testing is needed, including X-rays, ultrasound, or hysteroscopy.

Treatment

• Lifestyle changes may improve the ability to achieve pregnancy. These include cessation of cigarette smoking, reduction of alcohol and caffeine intake, maintenance of a healthy body weight, and regular physical activity.
• Timed intercourse, in which couples identify the fertile period to increase the rate of pregnancy, may increase the success rate by 30 percent or more. The most fertile time in a women's menstrual cycle is one to two days before ovulation.
• Medications (e.g., clomiphene, letrozole) can be effective when infertility is due to lack of ovulation. However, these medications significantly increase the risk for multiple gestations (twins, triplets, quadruplets, and quintuplets).  
• In vitro fertilization (IVF) has been used for more than two decades. In this procedure, several eggs are taken from the ovary, fertilized by sperm in a test tube, and then transferred into the uterus. IVF appears to be useful for many cases of infertility. However, further study is necessary to best define when IVF should be used.

Infertility: Nutritional considerations

• Antioxidant supplementation: Controlled studies of high-dose combinations of antioxidant supplements, including vitamin C (>200 mg/day), vitamin E (200-600 I.U./day), and selenium (100-200 μg/day), demonstrated improvements in sperm function and pregnancy rates.
  
  In infertile women, evidence of a role for antioxidant supplementation in achieving pregnancy is limited. Some studies have suggested a potential role for high-dose (750 mg/day) vitamin C and combinations of antioxidants, iron, and arginine supplements in achieving pregnancy.

• Carnitine: Carnitine is an amino acid that is concentrated within the epididymis (a small tube connected to the testicles) where it contributes directly to the energy supply required by sperm for growth and function. Supplementation with carnitine or acetylcarnitine (1.0-2.0 grams/day) has been shown to increase the number and function of sperm and the rate of pregnancy.

• Gluten-free diet in individuals with celiac disease: Celiac disease can impair fertility by delaying puberty, causing amenorrhea (lack of menstrual periods), causing malabsorption of key nutrients, or causing miscarriage. In individuals with celiac disease, fertility may be improved by following a gluten-free diet.
  

• Alcohol intake may impair fertility. Couples having fertility problems are advised to avoid alcohol. In men, alcohol consumption contributes not only to impotence, but also to a reduction of blood testosterone and impairment of sperm maturation. Alcohol consumption is also associated with decreased fertility in women.