The researchers studied 4,145 women and their children, ages 2 to 5, all members of Kaiser Permanente health care plans in Northern California. The women participants were racially diverse and all had a normal body mass index (BMI) before pregnancy, which according to guidelines established by the Institute of Medicine (IOM) means they should gain between 25 and 35 pounds during pregnancy.
The women who gained less than the IOM guidelines were 63 percent more likely to have an overweight or obese child. Similarly, women who gained more than the recommended weight were 80 percent more likely to have an overweight or obese child.
The study was published in the American Journal of Obstetrics and Gynecology. Study researcher Sneha Sridhar told the Journal: “Gaining either too little or too much weight in pregnancy may permanently affect mechanisms that manage energy balance in the offspring, such as appetite control and energy expenditure. This could potentially have long-term effects on the child’s subsequent growth and weight.”
The IOM guidelines
The following IOM recommendations were issued in 2009:
• Underweight: If you are underweight when you conceive, with a BMI of less than 18.5, your recommended range of weight gain is 28 to 40 pounds. During the second and third trimester, your target weight gain should be between one and 1.3 pounds a week.
• Normal: If your BMI falls between 18.5 and 24.9, you are considered normal weight. Your recommended rate of weight gain falls between 25 and 35 pounds, with a weekly weight gain in the second and third trimester between 0.8 and 1 pound.
• Overweight: With a BMI between 25 and 29.9 you are overweight, and your targeted weight gain range should fall between 15 and 25 pounds, averaging 0.5 and 0.7 pounds per week during your second and third trimester.
• Obese: A 30 or greater BMI signals obesity, and you should aim to gain between 11 and 20 pounds, with a 0.4 to 0.6 weekly weight gain the last two trimesters.
Overweight or obese?
In late 2012, The American College of Obstetricians and Gynecologists issued a statement that said women who are overweight and obese before conception may be able to gain less weight than IOM recommends as long as she is under the care of a doctor and the fetus is growing appropriately. The College also recommends that any obese or overweight woman considering pregnancy should lose weight before conceiving.
It’s important to remember that many overweight or obese women deliver healthy babies. However, overweight or obese women are at an increased risk for pregnancy complications, including:
• gestational diabetes
• difficulty hearing the heartbeat and measuring the baby
• cesarean delivery
In addition, cesarean deliveries pose a greater risk for overweight and obese women than for normal-weight women, including issues with anesthesia, blood loss, blood clots and infection.
Of course, medical care throughout the pregnancy can lower the risks of these complications. We also feel that all women, no matter their starting weight when they conceived, should avoid excessive weight gain during pregnancy, even more important now with the release of the Kaiser Permanente study.
Staying on target
The fundamentals of leading a healthy life – good food, exercise and sleep – are even more valuable for pregnant women since the weight gained during pregnancy provides nourishment for your baby and is stored for breastfeeding. The U.S. Department of Agriculture has devised a healthy diet based on six food groups, which barring allergies, we feel every pregnant woman should incorporate into her daily eating plan:
• Bread, cereal, rice and pasta
• Milk, yogurt and cheese
• Meat, poultry, fish, beans, eggs and nuts
• Fats, oil and sweets