Women who start their pregnancies at a normal weight are currently advised to gain at least 25 but no more than 35 pounds. Underweight women are told to gain more, overweight women less. But with the nation’s overall waistline expanding, the guidelines that set these ranges are being criticized as too lenient.
As a result, they could be revised downward, dramatically so, if some doctors and women’s health experts have their way.
“The concern is that it’s almost recommending too much weight gain for an average pregnancy,” says Dr. Michael Nageotte, president of the Society for Maternal-Fetal Medicine, who practices at Long Beach Memorial Medical Center.
More than half of women of childbearing age are overweight or obese even before pregnancy, federal statistics show. And some studies indicate that a third or more of women gain more than recommended during gestation.
Further, women who gain excess weight with two or three pregnancies may never get back to their starting point. Over time, those additional pounds contribute to diabetes, heart disease and other health problems.
The Institute of Medicine hopes to convene a committee later this year to explore how well the guidelines have been followed and whether there’s a need to revisit them.
“Excessive weight gain in pregnancy is probably one of the biggest contributors to female obesity,” says Dr. Sharon Phelan, a professor of obstetrics and gynecology at the University of New Mexico in Albuquerque.
And, Phelan adds, “It is exceptionally hard to lose that weight.”
Weight gain during pregnancy is a source of growing concern for doctors. Not only does it raise the risk of gestational diabetes and high blood pressure, which could lead to a preterm delivery with complications, for example, but it also can lead to bigger babies that cause more difficult deliveries and require more C-sections.
Research also suggests babies born to overweight women may be more likely to have birth defects and become heavy themselves.
According to the current recommendations, women of normal weight should gain 25 to 35 pounds during pregnancy, underweight women should gain 28 to 40, overweight women should gain 15 to 25 and obese women should gain at least 15.
The guidelines focus on weight gain associated with healthy babies. But now that obesity is such a problem in the United States, the effect of the weight gain on the mothers needs to be addressed, says Brenda Rooney, an epidemiologist at the Gundersen Lutheran Medical Center in La Crosse, Wis. Her research has shown that women who don’t lose baby fat within six months are more likely to be carrying it with them 10 or 15 years later.
Rooney says recent research on weight gain in pregnancy seems to indicate that a gain of up to 25 pounds may be appropriate for normal weight to overweight women.
But Dr. Raul Artal, professor and chairman of obstetrics, gynecology and women’s health at St. Louis University School of Medicine, would like to see women gain far less -- no more than 10 to 14 pounds for a normal weight woman, up to 16 to 20 pounds for an underweight woman and “very little” for overweight women.
He says women should essentially gain only the weight accounted for directly by the pregnancy -- which includes the fetus, placenta, amniotic fluid, increased blood volume and breast enlargement -- but not additional fat that’s usually included in estimates of healthy pregnancy weight gain.
“We’re not bears,” Artal says. “Pregnancy is not a time of hibernation.”
Fat stores may be needed in times of starvation, but most women in our super-size-me nation are eating too much.
Although most doctors would never recommend dieting, per se, during pregnancy, Artal says he has no qualms about counseling overweight patients to eat less. “For them, less could still be the diet of another person for a whole week,” he says.
One of his patients who recently gave birth weighed 520 pounds. The baby was so large that the mother had trouble in labor and needed a C-section, he says.
Other doctors say Artal’s weight-gain recommendations are extreme, but they agree the Institute of Medicine guidelines, while a good general guide, may be too permissive and, if strictly adhered to by all women, could encourage some to gain more than they should.
“I don’t want patients to feel pressure to gain weight in a healthy pregnancy,” Nageotte says.
Most babies tend to do just fine whether their mothers gain within the current guidelines or several pounds outside of them, he says.
Though very low weight gain in some women may cause a baby to be underweight, even babies born to mothers who’ve endured famine have fared well, he says.
“The fetus, being a very efficient parasite, if you will, is able to survive and get what it needs from the mother,” Nageotte says.
Several doctors, including Phelan and Nageotte, say a weight gain of 25 to 30 pounds is plenty for many women.
But even that upper limit can be too easily passed.
Gin Treadwell-Eng, a 33-year-old events coordinator, knows this firsthand. By the end of her first pregnancy, she had added 61 pounds to her 5-foot-5 frame.
Her blood pressure was normal and by all other accounts the pregnancy was healthy, but she hated the way she looked -- “I had a real hard time with it,” Treadwell-Eng says.
The Santa Clarita woman ultimately delivered a healthy baby girl, but it took her more than a year and a half to lose most of the weight -- and she never regained her pre-pregnancy weight of 145. She began her second pregnancy eight pounds heavier than the first.
Linda Meyers, director of the Institute of Medicine’s Food and Nutrition Board, which oversaw the 1990 guidelines, says her group thinks it’s important to look into whether the guidelines need to be updated because they are 15 years old, newer research has been done on the subject and obesity rates are rising.
“I think any time there’s active research in an area and new knowledge it pays to stop and take stock of whether it’s time to look further,” she says.
She notes that the Institute of Medicine’s Board on Children, Youth and Families is in the preliminary stages of organizing a workshop to explore issues of weight gain in pregnancy.
Rosemary Chalk, director of the children’s board, says that at the request of the federal Maternal and Child Health Bureau, she’s working to convene the Institute of Medicine committee this fall to “begin raising questions” about pregnancy weight gain. The bureau is part of the U.S. Department of Health and Human Services, but the committee would be under the auspices of the Institute of Medicine.
Regardless of guidelines, though, many experts say what’s most important is for pregnant women to focus on eating a healthy diet -- with a mere 300 additional calories per day -- than obsess about what the scales say.
“The weight gain is a proxy,” Phelan says. “It’s a clue to us about [a woman’s] nutrient intake.”
Due in November, Treadwell-Eng isn’t gaining as rapidly this time. She credits less nausea during her first trimester; she hasn’t eaten as much bread and crackers as before. And she’s trying to walk more.
So far, she’s put on 23 pounds -- about 20 pounds less than she had gained at this point in her last pregnancy.
“It’s better this time,” she says.