Fighting Infertility May Be Easier Than You Think
It's smart to quit smoking well before trying to get pregnant, too. A number of studies have shown that tobacco use can stretch the time it takes to conceive by a year or more, possibly because toxins in cigarette smoke accelerate the aging of a woman's eggs and damage the fallopian tubes. In fact, a 2006 study by Columbia University researchers found that women who smoked 14 cigarettes a day entered menopause an average of three years earlier than those who never smoked.
If you haven't ditched trans fats for other reasons already, this is a good time. A recent finding from the Harvard Nurses Health Study suggests that eating as little as 4.5 grams per daythe amount in one glazed Krispy Kreme crullercould disrupt ovulation. Study author Jorge Chavarro, a research fellow in the department of nutrition at Harvard School of Public Health, notes that the results need to be replicated before firm conclusions can be drawn but speculates that trans fats could indirectly lead to a rise in testosterone, which suppresses the function of the ovaries. "Check for the trans fat content on food labels, and avoid any foods with partially hydrogenated oils in the ingredients list," he advises. His research group also found a link between low levels of dietary iron and a failure to ovulate, possibly because iron is important for the maturation of the egg.
There isn't one ideal preconception diet, but emphasizing nonprocessed foods like whole grains, fruits, and vegetables will steer you away from trans fats. It's also wise to limit your intake of large fish such as tuna and swordfish, since the mercury they contain has been shown in animal studies to affect fertility. In terms of alcohol consumption, the consensus is that a glass of wine on occasion is probably fine. But how much alcohol is safe isn't known.
On the flip side, it's possible to be too fit. Women who work out intensely can have trouble getting pregnant, possibly because reproductive hormones are suppressed when the body interprets excessive calorie burning or physical stress as danger. A study published last fall in the journal Obstetrics & Gynecology found that those who regularly exercised four or more hours per week were 40 percent less likely to conceive after their first IVF treatment than sedentary women.
"Walking is fine, but spinning classes are out," says Alice Domar, an assistant professor of obstetrics, gynecology, and reproductive biology at Harvard Medical School and author of Conquering Infertility. "I generally recommend that my patients keep their heart rate below 110."
Couples who are actively trying to conceive need to understand some biology: Several hours before ovulation, the pituitary gland normally sends out a surge of LH, which causes the ovary's follicle to release an egg. But say you have a fender bender before the surge happens or suddenly discover you need a $10,000 roof repair. Such stresses can signal the pituitary gland that the body is in trouble, which slows the release of LH. If you have perfectionist tendencies, a single tear-your-hair-out day could be enough to disrupt ovulation that month, says infertility researcher Sarah Berga, a professor of obstetrics and gynecology at Emory University School of Medicine. Even if ovulation occurs, a shortage of LH could mean a shortage of progesterone, which is necessary to nourish and sustain a fertilized egg.