The authors also offer advice on when to seek a medical evaluation. If a woman is younger than 35 and hasn't conceived after 12 months of unprotected sex, the couple should consult with their doctor. If the woman is 35 or older, they should wait only six months. If the male has a history of treatment for cancer, surgery for undescended testicles or a varicocele, or if the female has a history of irregular or no menstrual periods, a history of cancer treatments with radiation or chemotherapy, or repeated miscarriages without successful births, the couple should seek help as soon as they start planning to achieve pregnancy.

Fertility Tips

Even in the best of circumstances, the chances that a woman will get pregnant are about one in four each month. Drs. Goldstein and Rosenwaks offer some tips on natural ways to boost fertility:

* Have sexual intercourse regularly, especially during the woman's most fertile time of the month. Couples seeking to get pregnant should have intercourse two to three times a week. They can also time sex for her most fertile period. As a rule of thumb, if she counts the first day of her period as day one, and she has regular periods every 28 to 30 days, the couple should try every other day starting on day 12 to 16 or so. Use ovulation kits available in pharmacies.

* Be healthy. Don't smoke, limit alcohol intake, reduce stress, exercise regularly and moderately, eat healthy foods, take vitamins and avoid environmental toxins. Men should avoid excessive heat and tight-fitting shorts. Women should limit caffeine intake and maintain some body fat.

* Check your meds. Medications like anabolic steroids that contain testosterone can reduce male fertility. Illegal drugs like heroin and cocaine can interfere with ovulation. Some drugs for hair growth, hypertension and Crohn's disease can also affect fertility. Check with your doctor.

SOURCE NewYork-Presbyterian Hospital/Weill Cornell Medical Center