Gaining both too much or too little weight during pregnancy appears to increase the risk of having an overweight or obese child, according to a Kaiser Permanente study published today in the American Journal of Obstetrics and Gynecology.
In one of the largest studies to examine current Institute of Medicine recommendations regarding pregnancy weight gain in relation to childhood obesity, researchers reviewed the electronic health records of 4,145 racially diverse female members of Kaiser Permanente in Northern California who had completed a health survey between 2007 and 2009 and subsequently had a baby. Researchers reviewed the medical records of those children between ages 2 and 5 years old and found that:
Among all women who gained more than the recommended weight during pregnancy, 20.4 percent of their children were overweight or obese, compared with 19.5 percent in women who gained less than recommended weight and 14.5 percent in women who gained weight within the guidelines.
Women with a normal Body Mass Index measurement before pregnancy who gained less than the recommended amount were 63 percent more likely to have a child who became overweight or obese.
Women with a normal BMI before pregnancy with weight gain above recommendations were 80 percent more likely to have an overweight or obese child.
“The stronger association we found among normal weight women who gained too much or too little weight during pregnancy suggests that perhaps weight gain in pregnancy may have an impact on the child that is independent of genetic factors,” said senior investigator Monique M. Hedderson, PhD, Kaiser Permanente Division of Research in Oakland, Calif.
“Gaining either too little or too much weight in pregnancy may permanently affect mechanisms that manage energy balance and metabolism in the offspring, such as appetite control and energy expenditure,” said the study’s lead author Sneha Sridhar, MPH, Kaiser Permanente Division of Research. “This could potentially have long-term effects on the child’s subsequent growth and weight.”
Starting BMI guidelines and weight gain recommendations used in the study are from the Institute of Medicine. For obese women (BMI of 30 or greater), the recommended weight gain during pregnancy is 11 to 20 pounds; for overweight women (BMI between 25 and 29), it is 15 to 25 pounds; for normal weight women (BMI between 18.5 and 25), it is 25 to 35 pounds; and for underweight women (BMI less than 18.5), it is 28 to 40 pounds.
For their children, overweight/obesity was defined as a BMI between ages 2 and 5 that was greater than or equal to the 85th percentile of the Centers for Disease Control and Prevention child growth standards.
In addition to Hedderson and Sridhar, co-authors of the study were: Jeanne Darbinian, MPH, Samantha F. Ehrlich, PhD, Margot A. Markman, Erica P. Gunderson, PhD, and Assiamira Ferrara, MD, PhD, all of the Kaiser Permanente Division of Research.
How much weight should I gain during my pregnancy?
It depends on how much you weighed before you conceived and how appropriate that weight is for your height. The relationship between your height and weight is expressed in a number called a “body mass index,” or BMI. You can calculate your BMI here.
The guidelines for pregnancy weight gain are issued by the Institute of Medicine (IOM), most recently in May 2009. Here are the most current recommendations:
If your pre-pregnancy weight was in the healthy range for your height (a BMI of 18.5 to 24.9), you should gain between 25 and 35 pounds, gaining 1 to 5 pounds in the first trimester and about 1 pound per week for the rest of your pregnancy for the optimal growth of your baby.
If you were underweight for your height at conception (a BMI below 18.5), you should gain 28 to 40 pounds.
If you were overweight for your height (a BMI of 25 to 29.9), you should gain 15 to 25 pounds. If you were obese (a BMI of 30 or higher), you should gain between 11 and 20 pounds.
If you’re having twins, you should gain 37 to 54 pounds if you started at a healthy weight, 31 to 50 pounds if you were overweight, and 25 to 42 pounds if you were obese.
Use our pregnancy weight gain estimator to find out how much you should gain (based on your height and pre-pregnancy weight) and to see how the pounds are distributed.
This research was supported by a grant from the Health Resources and Services Administration (R40MC21515).
About the Kaiser Permanente Division of Research
The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and society at large. It seeks to understand the determinants of illness and well-being, and to improve the quality and cost-effectiveness of health care. Currently, DOR’s 550-plus staff is working on more than 250 epidemiological and health services research projects.
About Kaiser Permanente
Kaiser Permanente is committed to helping shape the future of health care. We are recognized as one of America’s leading health care providers and not-for-profit health plans. Founded in 1945, our mission is to provide high-quality, affordable health care services and to improve the health of our members and the communities we serve. We currently serve approximately 9.1 million members in eight states and the District of Columbia. Care for members and patients is focused on their total health and guided by their personal physicians, specialists and team of caregivers. Our expert and caring medical teams are empowered and supported by industry-leading technology advances and tools for health promotion, disease prevention, state-of-the-art care delivery and world-class chronic disease management. Kaiser Permanente is dedicated to care innovations, clinical research, health education and the support of community health.