New Weight Gain Recommendations for Moms-to-Be

Over the past two decades, pregnancy has become a weighty issue. In 1990, the Institute of Medicine (IOM) recommendations on the amount of weight a woman should gain during pregnancy focused on women who didn’t gain enough weight, running the risk of delivering low-birth-weight babies. But as the years passed, the tables turned, and now, with two-thirds of the population overweight or obese, the agency said it recognized that the guidelines needed to be adapted to include heavier women. “In our population today, more women of reproductive age are severely obese (8 percent) than are underweight (3 percent) and their short- and long-term health has become a concern, in addition to the size of the infant at birth,” the new report reads.

According to the new guidelines, the heavier a woman is, the less weight she should gain during pregnancy. Underweight women, body mass index (BMI) of 18.5, should pack on 28 to 49 pounds if carrying a singleton; healthy women of normal BMI should gain 25 to 35 pounds; overweight women, BMI of 25 to 29.9, should gain 15 to 25 pounds; obese women, BMI of 30 of higher, should gain only 11 to 20 pounds. For women giving birth to twins: normal-weight women should gain 37 to 54 pounds; overweight women should gain 31 to 50 pounds; and obese women should gain 25 to 42 pounds. “It had become clear that heavier women could gain less weight and still deliver an infant of good size,” the report said.

The revised guidelines use BMI ranges set by the World Health Organization and the National Heart, Lung and Blood Institute, while the 1990 guidelines used tables from Metropolitan Life Insurance. The new recommendations are “not dramatically different from what was reported in 1990, but they are sort of progressive,” said Dr. Michael Katz, senior vice president for research at the March of Dimes, which co-sponsored the study. “They illustrate the substantial increase in obesity,” Katz said.

Women who put on too much weight during pregnancy risk not only keeping that weight after birth, but also have higher rates of complications, such as developing high blood pressure and gestational diabetes or requiring a C-section. “Preeclampsia is about twice as prevalent among overweight, and about three times as prevalent among obese women, as it is among normal weight women,” the report said. The World Health Organization estimates this condition kills 500,000 babies globally each year.

The report also emphasizes that women should get to a healthy weight before conceiving, and calls for women to be offered preconception counseling that includes their weight, height, physical activity and access to contraception for overweight or obese women who decide to use birth control as they move toward a healthier weight. This could result in better outcomes for both mother and child. “More women are already obese when they become pregnant. Based on data from the Pregnancy Risk Assessment Monitoring System, one-fifth of American women are obese at the start of pregnancy, a figure that has risen 70 percent in the last decade,” the report reads.

However, the new guidelines do not advise women to lose weight during pregnancy. “About half of reproductive-aged American women are trying to lose weight, and another one-third of pregnant women may be attempting to maintain their weight,” the report reads. “The prevalence of attempted weight loss during pregnancy doubled in the past 20 years.” Dieting during pregnancy increases the risk of neural tube defects (NTDs), in which the spinal cord and brain doesn’t fully develop. Diets that stress a high protein and low caloric intake, such as Atkins, have been linked to high levels of stress in offspring in their adult years. This raises the risk of high blood pressure and diabetes due to the increased level of the stress hormone, cortisol.

Instead, women of all sizes should eat a healthy, balanced diet while pregnant. This goal can be achieved by adding about 300-500 calories a day to their regular diet. But more important than the number of calories is the quality—fruits and vegetables, like spinach, carrots, oranges and tomatoes, are excellent for the immune system, while foods high in fat and sugar as well as caffeine should be avoided. Snacks should be nutritious as well.

To see how much weight you should gain during pregnancy, use the online calculator at www.nhibisupport.com/bmi/.

Check out the new HealthNews pregnancy and childbirth column, debuting next Saturday June 6th. Bringing in Baby: Pregnancy and Childbirth Made Healthy, written by Constance Rock, LM, CPM and Aleksandra Evanguelidi, LM, CPM, will run every Saturday and focus on all aspects of pre-pregnancy, pregnancy, childbirth, and early postpartum. Find out everything you need to know to have a healthy conception, pregnancy and birth.