Success. After taking control when trying to conceive

Tracy Ryan had given up hope of having a second child. Two years of trying to conceive, including three failed artificial inseminations, had finally culminated in a successful in vitro fertilization-and 2-year-old Christopher. But further attempts at IVF had left Ryan, 35, disappointed and exhausted.

Desperate to feel better, the stay-at-home mom from Fair Haven, N.J., decided to try acupuncture, kick her six-can-a-day Diet Pepsi habit, and eat more fish, fruits, and vegetables. Eight weeks later and slimmer by 7 pounds, Ryan was shocked to discover that she was pregnant. “I was literally shaking when I saw the pregnancy test,” she says. “My husband made me buy a different brand to verify it.”

Three artificial inseminations failed to work for Meredith Collins, but two relaxing vacations did
JARED LEEDS FOR USN&WR

Ryan can’t know whether to thank coincidence or her lifestyle changes for 9-month-old Brendan. But a growing body of evidence suggests that controllable factors (and not just a delay in childbearing) may be a reason 1 in 8 couples can’t conceive. Success depends on the delicately timed release of four reproductive hormones, and all sorts of factors-too little iron in the blood, too much or too little body fat, too much exercise-can throw the sequence out of whack. “We’re finding that everything matters-and moderation in terms of stress, body weight, diet, and physical activity is what’s important,” says Joel Evans, assistant clinical professor of obstetrics, gynecology, and women’s health at the Albert Einstein College of Medicine and author of The Whole Pregnancy Handbook.

No one is talking about magic bullets. Some women will do everything right and still get the maddening diagnosis of “unexplained infertility.” But institutions as well regarded as Duke University and Beth Israel Medical Center in New York are so convinced of the possibilities that they’ve recently opened “holistic fertility care” centers that offer women trying to conceive acupuncture, nutrition counseling, and relaxation classes. And a growing number of IVF clinics now host on-site yoga classes. At the very least, making healthful changes in the hope of improving your odds of a baby is bound to pay off in other ways.

Get ready. Sometimes, the body’s refusal to get pregnant can be a sign of its wisdom, says Tracy Gaudet, an obstetrician-gynecologist and executive director of Duke Integrative Medicine. Being overweight, for instance, puts a woman at risk of such pregnancy complications as high blood pressure, diabetes, and an abnormally large baby. So it may be no accident that excess estrogen produced by body fat interferes with ovulation. The body also may be saying “whoa” when a woman carries too little fat to sustain a growing baby: In underweight women, the pituitary gland releases less of the ovulation hormones FSH and LH.

Research from Harvard Medical School suggests that being at either end of the weight spectrum accounts for nearly 40 percent of failures to ovulate. Gaudet advises aiming for a body fat percentage in the range of 20 to 25 percent and a body mass index-a measure relating weight to height-of 20 to 25. That would equal about 117 to 145 pounds for someone 5 feet, 4 inches tall.

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 the toxins in cigarette smoke accelerate the aging of a woman’s egg 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 day-the amount in one glazed Krispy Kreme cruller-could 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 unprocessed 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.

Skipping meals or taking a long run when you’re feeling frantic might make matters worse. In a study of monkeys published last month, Berga and her colleagues created mild stress for one group by moving the monkeys in a new cage and found that 12 percent developed abnormal menstrual cycles. In the second group, which was moved plus given less food and a daily one-hour session on a treadmill, 70 percent experienced irregular menstruation.

Overcoming the level of stress associated with chronic infertility may require more formal interventions. On their first visit, about 40 percent of women seeking infertility treatments exhibit the same range and severity of symptoms-irritability, difficulty concentrating, sleep disturbances-as people diagnosed with an anxiety disorder, says Harvard’s Domar. She developed a 10-week workshop for infertile women now in use around the country that includes group therapy, nutrition counseling, and relaxation techniques such as deep breathing, meditation, and yoga. In two studies, Domar and her colleagues found that 55 percent of women who took the workshop while getting fertility treatment wound up giving birth to a healthy baby compared with 20 percent of women who had treatment alone. “The women who took the class were also less anxious and depressed and had a much easier time coping with the medical procedures,” Domar says.

Heidi Fallon, 36, of Ayer, Mass., found this to be true when she took Domar’s workshop at Boston IVF 15 months ago after going through three unsuccessful rounds of treatment and a miscarriage. The class taught Fallon focused breathing techniques that she used while stuck in rush-hour traffic and provided comforting connections with other infertile women. “They knew exactly what I was going through-how hard it was when a friend or relative got pregnant,” she says. An IVF cycle during the 10-week session produced Fallon’s 9-month-old triplets.

For some infertile couples, a phone call to a travel agent seems to do the job. “My friends raise their eyebrows whenever I take a vacation,” says Meredith Collins, 35, of Portsmouth, R.I. After three failed tries at artificial insemination, Collins took a much-needed break from her busy paint-your-own-pottery store and infertility treatments and headed to a beach in the Dominican Republic, where she promptly became pregnant with her now 19-month-old son. Her 6-month-old son was also conceived naturally on a 2006 family getaway to a quiet bed-and-breakfast.

Since the point is a healthy baby, success at getting pregnant doesn’t mean it’s OK to relax back into old habits. About 10 to 15 percent of pregnancies end in miscarriage, and lifestyle factors linked to infertility are probably responsible for some of them. In a study published last year, Danish researchers found that smokers had a higher risk of miscarrying during the first few weeks of pregnancy than nonsmokers. Stress, caffeine, and alcohol might also be associated with miscarriages, though the data have been conflicting.

Longer term, evidence is mounting that a pregnant woman’s lifestyle and diet can affect her baby well into adulthood. Children born to mothers battling depression or anxiety during pregnancy appear to be smaller and to weigh less as they grow, for example. The American College of Obstetricians and Gynecologists now recommends that clinically depressed women consider staying on their antidepressant medication while pregnant (with the exception of Paxil, which has been tied to birth defects). One recent study suggested that expectant mothers who eat more than three servings of fish a week deliver babies with higher IQs, while gaining too much weight during pregnancy seems to raise a child’s risk of developing obesity or diabetes as an adult.

And too little vitamin D puts babies at risk of asthma, type 1 diabetes, and bone deformities, says Lisa Bodnar, an assistant professor of epidemiology at the University of Pittsburgh whose research shows that, even with prenatal vitamins, most pregnant women aren’t getting enough. She recommends at least 1,000 international units of vitamin D a day; most prenatal supplements contain 400 IUs. Clearly, there’s good reason to make choices that go beyond standard practice. But most are common sense.

This story appears in the May 7, 2007 print edition of U.S. News & World Report.