Illustration: Mark Matcho for Newsweek

 By Karen Springen

Like many couples, Brian Delaney, 35, and his wife, Daniela, 34, turned to in vitro fertilization after failing to conceive on their own. But after five attempts and an investment of $150,000, IVF failed them as well. Then Brian saw a male-infertility specialist, Columbia University’s Dr. Harry Fisch, who discovered that Brian’s low sperm production could be corrected through microsurgery. Three months later, Daniela was pregnant. Last November she delivered a baby boy, Harrison.

Long overlooked, male infertility has become a fruitful field of research. Doctors now know that, when a couple fails to conceive, the problem lies with the man as often as with the woman. And as the Delaneys learned, recent advances have dramatically improved experts’ understanding of how to diagnose, treat and prevent the condition. “Anything that makes the body unhealthy—a disease, toxins, excessive alcohol—will hurt fertility,” says UCSF urologist Paul Turek. “But most of these things that hurt fertility are reversible.” Some tips for men:

Prune your prescriptions. Among the commonly prescribed medicines that can affect fertility or libido are SSRI antidepressants like Prozac, beta blockers for hypertension, alpha blockers like Flomax (used to treat the symptoms of an enlarged prostate), the stomach-ulcer drug Tagamet and pain medications like morphine and oxycodone.

Men who are trying to conceive should also avoid using anabolic steroids and testosterone creams and injections because they shut down the body’s production of testosterone and sperm. “The body loves it, but the testicles hate it,” says Turek. “They say, ‘Well, there’s plenty of testosterone. I don’t need to make testosterone or sperm myself’.”

Have more sex. It sounds obvious, but some busy couples don’t make enough time for it. During ovulation—about 10 to 18 days after a woman’s period starts—couples should have sex every other day to “optimize sperm motility,” says Fisch, who is also the author of “The Male Biological Clock.” After five days without sex, a man has a higher volume of fluid, which dilutes the concentration of sperm and makes them less active.

Stay fit. Doctors are seeing more men with obesity-caused infertility. Fat converts testosterone to estrogen, and obese men (or those with a waist circumference of more than 40 inches) are more prone to erectile dysfunction. Men with type 2 diabetes, often associated with obesity, are more prone to low testosterone levels, which negatively affect libido and sperm production.

Doctors can prescribe anti-estrogens like Clomid, used to increase egg production in women, to stimulate testosterone production and, in many men, sperm production.

Stay cool. Heat can damage sperm cells, so stay out of hot tubs, avoid putting your laptop on your lap and don’t sit for long periods of time with your legs crossed or pressed together, says Dr. Peter Schlegel, chairman of urology at NewYork-Presbyterian/Weill Cornell Medical Center in New York. There’s also some evidence linking cell-phone radiation with altered sperm cells in men, so don’t “live on the cell phone,” and keep the device in your jacket or holstered to your belt rather than in your front pants pocket, he says.

See a urologist. “Even those men who we considered to be sterile in the past, we almost always can treat them now,” says Schlegel. Urologists can provide treatments such as vasectomy reversals and outpatient microsurgery for conditions like blocked ducts, scarring from STDs and varicoceles, a type of varicose vein.

Men who want to boost their fertility should also quit smoking, cut back on alcohol, avoid illegal drugs (especially marijuana) and exercise regularly. “Anything that improves medical health is likely to improve sperm,” says University of Illinois at Chicago andrologist Craig Niederberger. Then be patient. “In the world today, people want to act too quickly. ‘We tried for two months, we didn’t get pregnant, we want IVF’,” says urologist Robert Oates, director of male reproductive medicine and surgery at Boston University School of Medicine. Sometimes “try, try again” comes with its own rewards.