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A Weighty Issue

One of the earliest tip-offs to being pregnant with each of my three children -- besides rock-solid, sore boobs that sent lightning bolts through my chest if I attempted any movement beyond a slow saunter -- was how much I began eating. Suddenly I was starting the day with bacon, eggs, and toast, followed by a mid-morning muffin. And all this before the telltale missed period.

Apparently, I'm not alone: Our growing cultural tendency to eat more fast food, more junk, more empty processed calories, and just more in general -- even when it's a nutritious meal -- all while we sit in front of the TV or computer screen, means many women are either too heavy before pregnancy or gain too much during it. According to the most recent statistics from the Centers for Disease Control and Prevention (CDC), almost one-fourth of women 25 to 55 years of age are overweight, and another quarter are obese, which means half of all women may be entering pregnancy with preexisting weight problems. When they do become pregnant, 38 percent of normal-weight women and 68 percent of overweight women see the scale soar higher than the recommended guidelines for gestational weight gain, according to a study by researchers at Cornell University, in Ithaca, New York, and funded by the National Institutes of Health.

This trend presents a serious threat to babies. If a woman is overweight or obese during pregnancy, she's at greater risk of complications and birth defects that can compromise the health of her child. It has implications for her own health as well: In a recent Gallup survey, 78 percent of female ob-gyns cited obesity as the number one health threat to American women.

Knowing you'll never again put on a bathing suit without wincing may not be enough to make you pass on the dulce de leche, and worries about your future health may seem too far off to sweat right now, but surely the motivation to have a healthy baby can propel you toward better pregnancy nutrition. Here's the latest research about the importance of a healthy pregnancy weight gain -- and advice that can help you achieve it.

Risk factors you need to know

Whether you are over- or underweight is determined by your body mass index, or BMI. Your health care practitioner can help you calculate your BMI, or you can do it yourself with this formula: Multiply your weight in pounds by 703, then divide that answer by your height in inches. Divide that answer again by your height in inches. That number is your BMI. (For instance, a 120-pound, five-foot four-inch woman would have a BMI of 20.6.) The CDC categorizes a BMI of 18.5 or less as underweight, 18.5 to 24.9 as healthy weight, 25 to 29.9 as overweight, and 30 or higher as obese.

With half of all reproductive-age women tipping the scales above their recommended weight, it's not surprising that there's been a corresponding rise in the rates of the infant health conditions associated with heavier moms-to-be. While obese pregnant women are most likely to suffer from these complications, researchers are finding that those who are overweight are at risk as well.

Several recent reports have highlighted the following increased dangers:

Overweight and obese pregnant women have higher rates of preterm birth. Heavy pregnant women are more likely to suffer from gestational diabetes and preeclampsia (pregnancy-induced hypertension) -- both of which increase the odds of preterm labor. A March of Dimes report, Nutrition Today Matters Tomorrow, points to a direct link between the soaring rates of obesity among women of childbearing age and the increased rate of premature birth, which has risen 23 percent since the early 1980s. Prematurity puts infants at significantly increased risk of a host of lifelong health problems: developmental delays, chronic lung disease, and cerebral palsy to name a few. In fact, preterm birth is the number one cause of neonatal death in the first month of life.

Infants born to heavy women are more likely to suffer from birth defects. Research from the March of Dimes found that overweight and obese women were reported to be 30 to 40 percent more likely than healthy-weight women to deliver a baby with a major birth defect, in particular a neural tube defect, which affects the brain (anencephaly) or the spine (spina bifida).

Not only that, a study of 900 California women published last November in the American Journal of Clinical Nutrition found that obese women who ate a large amount of high-glycemic foods (such as white bread, cookies, sugary cereals, and soft drinks) around the time of conception were at greater risk of having a baby with a neural tube birth defect. "Prior research has indicated that obese women have a twofold increased risk of these defects," notes Suzan Carmichael, Ph.D., an epidemiologist with the California Birth Defects Monitoring Program, which conducted the study. Their results showed that obese women who reported eating the largest amounts of high-glycemic foods during early pregnancy had four times the risk of neural tube defects.

"While we don't know the exact reason, it's possible that obesity contributes to a problem with blood-sugar control," says Carmichael. High-glycemic foods tend to make blood sugar soar; in contrast, the unrefined carbohydrates in fiber-rich whole grains, beans, and vegetables result in a slower release of sugar into the blood and help you feel full longer. "We don't want to be alarmist -- eating a sandwich on white bread will not hurt your baby. Still, the best route during pregnancy is to follow the recommendations of eating high-fiber, less-processed, and calcium-rich foods, as well as fruits and vegetables."

A study published in the May 2003 issue of Pediatrics entitled "Maternal Influences on Child Health," had similar conclusions: It found a link not just between obesity and neural tube defects but also between being overweight and an increase in congenital heart problems as well as "multiple defects" (when a child suffers from more than one major malformation).

Heavy women are more likely to have a cesarean delivery. Another study in Pediatrics found that women who gain excess weight during pregnancy account for a growing proportion of cesarean deliveries (which are now up to 26 percent nationwide, according to the CDC, the highest ever recorded) because excess weight is associated with overly large fetuses that can't be delivered vaginally. Gestational diabetes (more common in heavier women) can also cause the fetus to grow too large. "Bigger babies are at higher risk of experiencing shoulder distocia during delivery -- the head may make it out, but the shoulders get stuck," notes Marcos Pupkin, M.D., chairman of obstetrics and gynecology at Mercy Medical Center, in Baltimore. "Then, we are forced to try to reposition the fetus, which can cause trauma to the baby. In some cases, we must do a cesarean, and there is a greater risk of infection to the mother because there are so many more layers of fat to cut through." Even in the best circumstances, c-sections are considered major surgery and incur risks for the mother, including complications from more extensive anesthesia and the possibility of hemorrhage due to a surgical accident, not to mention a longer and more painful recovery period.

Being overweight or obese compromises a woman's future health. Heavy women have a higher risk of heart disease, diabetes, certain cancers, and arthritis. Postpartum, a heavy woman is much more likely to retain the excess weight, compounding the problem with each successive pregnancy. "Women who gain more than the recommended amount during pregnancy are more than four times as likely to be obese one year after giving birth," says Christine Olson, Ph.D., professor of nutritional sciences at Cornell.The best way to put on pounds

The safe and smart amount of pregnancy weight gain depends on the individual mom, how much she weighed beforehand, and her dietary and lifestyle habits. A decade ago, the Institute of Medicine raised the recommended pregnancy weight gain to 25 to 35 pounds, to ensure optimum nutrition for the fetus. (Previous generations had been advised to gain less, with about 22 pounds being average in the 1960s.)

That standard is intended for women entering pregnancy at a normal weight. Those who are underweight should gain 28 to 40 pounds; those who are overweight, 15 to 25 pounds; and those who are obese, 15 pounds, according to the American College of Obstetricians and Gynecologists (ACOG). Within those 10- to 15-pound ranges, the low end is what the baby needs to thrive, and the high end is the limit at which moms need to stop gaining or risk their own future health, says Hope Ricciotti, M.D., assistant professor of obstetrics and gynecology at Harvard Medical School and author of The Pregnancy Cookbook. Your health care provider will suggest an appropriate weight gain based on your BMI and possibly factor in other issues, such as activity level. To gain the average of 28 pounds, Dr. Ricciotti recommends adding just 100 calories a day during the first trimester, followed by a careful, gradual increase to about 200 extra calories a day as you start the second trimester, and then 300 to 500 extra as you start the third. Translated into pounds, that means gaining about 3 to 6 pounds in the first trimester, and 6 to 12 pounds in both the second and third trimesters. Another way to look at it is 10 pounds in the first half (20 weeks) of pregnancy, and 18 pounds in the second half.

Women who are very physically active or have tall, big-boned frames may be able to add as many as 500 additional calories and still stay within the recommended weight guidelines. On the other hand, heavier short women may be advised to stay at the lower end of the weight-gain range, says Dr. Pupkin. Young or African-American mothers-to-be may be told to gain at the higher end of the range because they have higher rates of preterm birth and low-birthweight babies.Avoiding pound pitfalls

There are two critical times to focus on what you're eating during pregnancy, says Mary Jane Lewitt, a certified nurse midwife in Atlanta and a spokesperson for the American College of Nurse-Midwives. The first is early in your first trimester, when you should evaluate your eating habits with your health care practitioner and figure out what you need to work on. The second is at the halfway point to determine if you're where you should be weight-wise and to make changes if you're not. Beware of these common pitfalls along the way:

Stay trim in your first trimester. As noted earlier, little weight gain is necessary early on. Stick to small increases in dietary protein at this stage -- only about 10 to 15 extra grams are required during pregnancy, for a total of about 60 grams a day. Three ounces of lean meat provides 15 to 20 grams, for instance, as does about 2 cups of milk or a cup of yogurt together with an ounce of cheese. If you balloon by 10 pounds or more before 20 weeks, it's probably not what you're eating but how much, notes Dr. Ricciotti. "Women get a lot of distorted messages about eating for two. If you're gaining too quickly, your doctor may suggest that you reduce your portion sizes by 10 to 15 percent," she says. "Focus on getting the recommended servings of fruits and veggies so you're filling up on healthy, low-calorie choices. It's not the end of the world if you gain 10 pounds in one month, but it becomes more worrisome if you do it again the next month."

Read recommendations carefully. No matter what the charts say, there's no need to force yourself to eat more than you feel comfortable with, especially when heartburn sets in. Nine servings of grains sounds like an awful lot, until you realize that a typical bowl of cereal is the equivalent of two to three servings. Don't forget that many foods can be counted as more than one food group: A chicken-and-broccoli stir-fry includes both vegetable and protein servings -- and grains, too, if you eat it with brown rice.

Maintain at least a moderate level of physical activity. From M.D.'s to midwives, R.D.'s to R.N.'s, the consensus is to keep weight gain on track with regular exercise, ideally for at least a half hour three times a week. "You can safely do prenatal yoga and light weight training, and use cardio equipment like elliptical trainers and treadmills," notes Dr. Ricciotti. Start slow, avoid overheating, and talk to your health care provider, especially if you haven't been exercising. For the out of shape, the best bet is to start a walking program, which is always safe during pregnancy. If you're starting out your pregnancy in good physical shape, daily vigorous exercise is fine as long as you avoid activities that can interfere with balance, cause injury to the abdomen, or have a high risk of falling. These include skiing (both water and downhill), surfing, horseback riding, cycling, diving, and snowmobiling. And there's more to pregnancy exercise than meets the scale: That added muscle tone and stamina may well help you endure the rigors of labor, too.

Ditch (some of) the desserts. As with any real-world diet, thinking you're never going to be able to treat yourself is bound to backfire. "Being pregnant may not mean having dessert at every meal, but it also doesn't mean you have to be perfect," notes Dr. Ricciotti. Have some cookies or ice cream in moderation two or three times a week if you're on track weight-wise. Or buy yourself a box of really good chocolates and savor one each night before bed.

Take care of yourself. While plus-size women are at greater risk of pregnancy complications, being overweight isn't a reason to avoid getting pregnant. And the last thing you would ever want to do if you're gaining too quickly would be to go on a crash diet. Ideally, the health risks to a baby will be an incentive to eat healthfully and be vigilant about prenatal care. "Start a nutritious eating and exercise plan now," adds Lewitt, "so you can have the best possible outcome for your baby."

Stephanie Wood, a mother of three, lives in Blauvelt, New York, and writes frequently about pregnancy and parenting. She is the coauthor of The Epidemic.