February 22, 2005 -- Tonja Schnelle's first pregnancy was progressing normally -- until she hit 32 weeks.
Then the Belair, Md., resident was diagnosed with preeclampsia -- pregnancy-induced hypertension -- that put her child at risk. Schnelle, considered obese at 190 pounds with a body mass index (BMI) of 30 before pregnancy, was put on bed rest. The plan was to deliver the baby early.
But just before Schnelle's scheduled cesarean section at 37 weeks, she felt explosive pain high in her abdomen. Monitors showed that the baby's heartbeat was dropping precipitously.
The last thing Schnelle remembers was doctors searching frantically for a fetal heartbeat. While they rushed to operate, the placenta ripped away from the wall of the uterus, cutting off the baby's oxygen and causing Schnelle to hemorrhage. When Schnelle awoke from anesthesia, the baby girl had died.
"I was stripped of motherhood," said Schnelle, now 30. "It was devastating." Fifteen months later, Schnelle is again expecting a girl. This time Schnelle is working hard to reduce risk factors for preeclampsia. At 18 weeks, she saw a nutritionist who prescribed a 2,000-calorie-a-day diet spread out among six healthy meals. Schnelle is also making an effort to be more active.
"Weight is one of the major risk factors for preeclampsia and one of the few things you can do something about," said Schnelle emphatically. "So you have to do everything you can to control it."
Somehow, the spotlight on the national obesity epidemic has missed its powerful impact on one particular subgroup -- women expecting a child. Experts estimate that of the 6 million U.S. women who are pregnant at any given time, about 3 million are overweight or obese. These women are at increased risk for preeclampsia, gestational diabetes and cesarean sections, and their offspring are more likely to be obese themselves. The babies are also more likely to be born prematurely, to have birth defects or to be stillborn.
While few major public health efforts have addressed the issue to date, the problem is recognized as a serious one.
"[Obesity] has a major impact on pregnancy outcomes," said Laura Riley, director of obstetrics and gynecology and infectious disease at Massachusetts General Hospital and assistant professor of obstetrics and gynecology and reproductive pathology at Harvard Medical School. "It's a hugely important medical problem."
Packing It On
At a time when 65 percent of U.S. adults are overweight (defined as having a BMI of 25 to 29.9) or obese (a BMI of 30 or higher), according to the Centers for Disease Control and Prevention (CDC), it's not surprising that many women of childbearing age would be affected. But the size -- and cost -- of the impact are daunting.
More than half of all women age 20 to 39 are overweight or obese, according to 2001-2002 data from the National Health and Nutrition Examination Survey (NHANES), which since 1960 has measured overweight in the U.S. population.
Add unrestricted food intake during pregnancy to that, and you have women exposing themselves to serious risks. The Institute of Medicine recommends that women of a healthy weight gain 25 to 35 pounds during pregnancy, that overweight women gain 15 to 25 pounds and that obese women gain no more than 15 pounds. The longstanding advice to "eat for two" was revoked by the American College of Obstetricians and Gynecologists (ACOG) in 1982. In 2002, according to the CDC, 21 percent of all pregnant women gained 40 pounds or more with their pregnancies. That's up from 15 percent in 1989.
A recent study by the University of North Carolina and the National Institute of Child Health and Human Development found that 69 percent of healthy-weight women gained "excessive" amounts during their pregnancies; among overweight women, the figure was 85 percent; among the obese, 79 percent.
"The timing on this couldn't be worse," said Riley. "It dovetails with the disturbing obesity epidemic and unhealthy foods being super-sized."
Lately, more studies are focusing on the dangers of overweight during pregnancy. In November a British report found that one in three women who die in the United Kingdom during pregnancy, in childbirth or just after labor, is grossly overweight, and that their deaths are often attributable to problems caused by obesity. U.S. experts say they would expect similar findings if such a study were done here.
A study published Oct. 29 in the journal Obstetrics and Gynecology showed that overweight and obese women progress more slowly through labor, thereby incurring a greater risk for cesarean sections. For overweight women, such operations pose greater risks of life-threatening complications, including blood clots, infection, wound complications and excessive bleeding.
Last spring, a Swedish study showed that women who gain more than 35 pounds during pregnancy are more likely to be overweight 15 years later. The added weight, researchers found, put them at higher risk for a cascade of health problems, including high blood pressure, heart disease, stroke, diabetes, depression -- and the list goes on.
These newly documented risks join those already established for women who are overweight during pregnancy: gestational diabetes (a form of the disease, usually temporary, that comes on during pregnancy); preeclampsia (a possible consequence if gestational diabetes is not properly controlled) and the need for a cesarean section. Women who develop preeclampsia are more likely to have high blood pressure after the baby's birth. Likewise, women who develop gestational diabetes have an increased chance of developing type 2 diabetes later in life.
For women looking to avoid such problems, timing is everything: It's far easier -- and safer -- before becoming pregnant than after. Because of risks to the fetus, doctors generally discourage dieting during pregnancy unless you're working closely with a doctor and/or nutritionist.
Lethal Inheritance
And then there are the risks to the babies.
A May 2003 study in the journal Pediatrics showed that babies of obese and overweight women have twice the risk of congenital heart defects and multiple birth defects. The study, conducted by CDC researchers, showed babies born to obese women are also at least three times as likely to be born with a defect known as omphalocele, in which intestines or other abdominal organs protrude through the navel. (Surgery can correct this problem.) Babies with obese mothers are also more likely to have neural tube (spinal cord and/or brain) defects, including spina bifida, a neurological condition that can cause a portion of the spinal cord to develop outside the body.
Other elevated risks to babies attributable to overweight include stillbirth; premature delivery (as a result of preeclampsia); and macrosomia, a condition in which the baby's chest and trunk grow too large to fit easily through the birth canal. Babies with this condition sometimes sustain permanent nerve damage to the shoulders during delivery.
Even those who escape infancy relatively unscathed don't get a pass on long-term risks. A study published in January in the American Journal of Clinical Nutrition found that by age 6, children of overweight mothers are 15 times more likely to be obese themselves than are the children of normal-weight mothers. And recent research by British and Swedish researchers found that women who were heavier than average at birth -- as babies born to overweight women often are -- have a sharply higher rate of breast cancer before age 50. A new study in the International Journal of Cancer showed that bigger babies also seem to have a greater risk of developing certain blood and digestive tract cancers as adults.
"The biggest tragedy of all is what happens to these children. They are committed to lifelong struggle and lifelong medical risk," said ACOG president Vivian Dickerson, an associate professor at the University of California, Irvine (UCI), and director of the division of general obstetrics and gynecology at the UCI Medical Center.
Awareness, or Lack Thereof
Why aren't women more aware of the risks of being overweight while pregnant? Often, some critics say, their doctors don't bring it up.
"Clinicians get numb to it because everyone's like this -- overweight," said Ellen J. Landsberger, assistant professor of obstetrics and gynecology and women's health at Albert Einstein College of Medicine in New York, who is also a maternal-fetal sub-specialist and a nutritionist.
Then, too, tackling obesity isn't always straightforward.
"There's a whole lot of stuff involved in obesity -- body image, self-image, sense of self-worth. It can be overwhelming to try and deal with that in one visit," said Dickerson.
As ACOG's president, Dickerson said, she presses obstetricians and gynecologists to counsel patients about weight before pregnancy. "A doctor wouldn't ignore it if their patient had blood pressure or blood sugar problems," she said. "So ignoring a weight issue is not consistent with good medicine."
She also lectures to lay audiences in the hopes of reaching women with the message. ACOG, she said, is considering releasing a committee opinion on obesity and pregnancy to draw greater attention to the problem.
A few organizations have taken steps of their own. Last year, the March of Dimes launched an awareness campaign on maternal obesity, and placed a few obesity-focused nutrition education pages on its Web site. Some weight-loss programs have a prenatal or pregnancy component, and some gyms have programs for pregnant women.
But for the most part, it's up to women to seek out nutrition and exercise guidance to avoid obesity in pregnancy -- and in their offspring.
"What one weighs going into pregnancy is one of the few things about pregnancy that women can control," said Schnelle, who began her second pregnancy at 220 pounds -- still obese -- but has added only 15 pounds in the following 32 weeks, compared with the 70 pounds she gained in her last pregnancy. "If your weight isn't controlled, you can face unexpected outcomes, like the tragedy I was hit with. Losing a child because of a disorder that has links to being significantly overweight just shouldn't have happened. It didn't need to happen."
Suz Redfearn last wrote for the Health section about Georgetown's new Center for the Study of Sex Differences.
