Revisions in the amount of weight obese women should gain during pregnancy didn't go far enough, some doctors say. Obese patients should not gain any weight during pregnancy, meaning women could weigh less after delivery than when they became pregnant.

The surging U.S. obesity rate and new research on the consequences of gaining too much weight during pregnancy prompted the change two years ago weight gain guidelines. The recommended amount for obese mothers-to-be was lowered to 11 to 20 pounds.

One of the doctors against the change is Dr. Raul Artal, director of obstetrics at St. Mary's Health Center in Richmond Heights and chair of the obstetrics and gynecology department at St. Louis University School of Medicine.

The guidelines, released by the Institute of Medicine, "are not based on reality," Artal said. "They may even be contributing to America's increasing waistline. I consider pregnancy as the main contributor to the obesity epidemic in this country," he said.

While some research suggests fewer complications among obese women who gain little or no weight, the idea is controversial. Experts warn the evidence is still lacking.

"There's no reason to tell them to lose weight," said Kathleen Rasmussen, professor of nutrition at Cornell University and chair of the committee that wrote the latest guidelines. "The data for those women is quite clear ... they have better outcomes if they gain between 11 to 20 pounds, and that's across all the outcomes that we examined, for mother and baby, and long and short-term."

GUIDELINES CHANGE

Weight gain guidelines have climbed steadily over the decades. In 1970, concerned that doctors' orders to gain less than 20 pounds were resulting in too many low birth weight babies, experts recommended women gain 20 to 25 pounds.

The guidelines changed again in 1990 with the creation of weight categories, still with a focus on improving low birth weight rates. Those guidelines were: 28 to 40 pounds for underweight women, 25 to 35 pounds for normal-weight women, 15 to 25 pounds for overweight women and at least 15 pounds for obese women.

Emerging health concerns, especially the increasing number of women who are overweight and obese, prompted the latest revisions.

One in four women are obese at the start of pregnancy, a figure that has doubled since 1990, national figures show. The percentage of women who gained more than 40 pounds during pregnancy also rose to 20 percent from 15 percent.

In Missouri, nearly half of all births are to mothers who are overweight or obese, according to the latest figures from 2009, a number similar to the rest of the country.

The increased risks are serious and lifelong. Obese pregnant women have a higher risk of stillbirth, preeclampsia, hypertension and blood clots; and their babies have a higher risk of early neonatal death, birth defects and being too big, according to the U.S. Centers for Disease Control and Prevention. Obese women also more likely to deliver by caesarean section, a riskier surgery for them than for normal-weight women, and suffer complications with anaesthesia.

"We know that 18 to 20 percent of the causes of maternal mortality are related to obesity and its complications during pregnancy," Artal said.

Overweight or obese women are also more likely to develop gestational diabetes which puts them at an every greater risk of developing full-blown diabetes after they are pregnant.

'VICIOUS CYCLE'

Overweight and obese women are more likely to gain too much while pregnant and more likely to retain the weight after delivery, resulting in riskier subsequent pregnancies and increasing the risk lifelong health problems such as cancer and cardiovascular disease.

"It's kind of a vicious cycle," said Dr. Naomi Stotland, assistant professor at University of California, San Francisco, who has studied weight gain and pregnancy. "Whatever predisposes them to being overweight in the first place predisposes them to keeping weight on after pregnancy."

A recent study found that at one year postpartum, almost 25 percent of women retained at least 10 pounds of the weight gained during pregnancy, a problem that's gotten doctors' attention.

Among policies adopted at the American Medical Association's annual meeting last month, doctors advocated for referrals of pregnant and postpartum patients to nutrition counseling and that the counseling be covered by insurance.

Women gaining excessive weight during pregnancy could be contributing to America's increasing waistline another way: New research shows their babies are predisposed to being overweight later in life.

A few large studies released within the past five years — including one involving Artal's research of birth certificate data from 120,000 Missouri women — found that obese women who gained little or no weight experienced fewer pregnancy complications, especially among morbidly obese women. Some of the research, however, also found an increased risk having a low birth weight baby but suggest the benefits outweigh the small risk.

Rasmussen insists the latest data and safety for mom and baby were considered in developing the 2009 guidelines, which she called "a radical change in health care for women."

'CAN'T SHRINK' BABY

Artal, however, called the guidelines "anachronistic." He said they "reflect the same concepts popularized in the '80s and '90s." He, along with colleagues at Yale and Duke universities, published a commentary last year in the medical journal Obstetrics criticizing the 2009 guidelines for maintaining the focus on low birth weight.

"They do not take into consideration the short-term and long-term complications for the mother," Artal said. Better ultrasound technology allows doctors to intervene when they detect a fetus lagging behind in growth, he added.

"But if a baby is too large during pregnancy, you cannot shrink it," he said.

Rasmussen said the committee was also concerned about studies showing that babies born to mothers with a high number of ketones — substances produced in the blood when the body burns stored fat as energy — had learning problems and lower IQs later in life.

"What we don't have any information on is the long-term neurological development of the fetus," when moms-to-be lose weight, Rasmussen said, who added that guidelines must err on the side of caution.

The ketone studies have been disputed, but prenatal check-ups continue to involve checking ketone levels in urine.

Artal said he decided long ago the benefits are clear. Since the mid 1990s, he said, he's been urging his obese patients to gain no weight. He has seen healthier moms and babies among those who are able to follow his advice, he said. Even for women in the overweight category, he thinks little weight gain is ideal.

"Our data shows optimum pregnancy outcomes in women who gain 10 pounds," he said of overweight women. Gaining more, he said, increased their likelihood of getting gestational diabetes.

The key is to diet safely, he said. He asks his patients to eat six nutritious small meals a day that total 2,000 to 2,500 calories. He also wants them to walk 30 minutes a day.

Pregnancy can be an ideal time to encourage difficult lifestyle changes and affect the obesity epidemic, Artal said, because women are motivated to follow doctors' orders.

That was true for Ariene Naber, 30, of St. Louis, who is 5 feet 4 and weighed 182 pounds when she got pregnant last year — just barely in the obese category. At 31 weeks, she was transferred to Artal's high-risk clinic after gaining 14 pounds and being diagnosed with gestational diabetes.

"I went into whatever-I-need-to-do mode," Naber said. For the last two months of her pregnancy, she gained no weight. She delivered a health baby girl on Nov. 22 and had an uncomplicated, vaginal delivery.

Naber has continued her newfound habits and now weighs 20 pounds less than before pregnancy.

"I do feel like it was definitely an eye opener to how life can be if I don't watch it ... and seeing I can control my weight with a better diet," she said. "My goal is to get to a healthy weight and healthier lifestyle before I get pregnant again."

More rigorous studies are under way in Oregon and Australia. Scientists are hoping the results will provide a clear verdict on the safety of weight loss during pregnancy. The studies also may shed some light on how best to help women stay within the current weight gain guidelines, which some say is a more realistic goal.