Weight Gain During Pregnancy

Recommendations regarding the amount of weight women should gain during pregnancy have changed over the past century. Here is a summary of the most recent update.
Weight Gain During Pregnancy

The 2009 Recommendations
In 2009, the Institute of Medicine (IOM) updated its recommendations on weight gain during pregnancy. These recommendations for total and rate of weight gain are based on WHO body mass index (BMI) categories. 1 The recommendations are that underweight women, those with a BMI, <18.5 gain 28-40 pounds at an average rate of 1 lb/week during the second and third trimesters, those at a healthy weight (BMI 18.5-24.9) gain 25-35 pounds at the same rate of 1 lb/week, overweight women (BMI 25-29.9) add 15-25 pounds at a little more than half a pound each week, and obese women (BMI ≥ 20) gain 11-20 pounds, at a half a pound weekly during the second and third trimesters.

Why Excess Weight Gain is Discouraged
IOM workshops have assessed the effects of pregnancy weight gain on both the mother's and child's health. In addition to concerns about excessive weight gain on maternal health, evidence is showing that prenatal weight gain can also have long-term effects on the child's welfare.

For example, a study published in the American Journal of Obstetrics and Gynecology found that greater weight gain during pregnancy resulted in children who weighed more and had more body fat and a higher systolic blood pressure at the age of 3. 2 Further, a study published in the American Journal of Perinatology found that being obese at the start of a pregnancy and a weight gain of more than 35 pounds was linked with a greater risk for four poor postnatal outcomes. The author of this study concluded that their results strongly support that women should strive to achieve a healthy weight prior to conception and then avoid excess gain during pregnancy. Doing so, they say, will lead to a better birth experience in obese and overweight women. 3

Excess pregnancy weight also can be hard to get rid of. In a group of Swedish mothers followed for 15 years, the women who gained more than the recommended amount of weight or did not return to their pre-pregnancy weight were more likely to have continued weight gain with subsequent pregnancies. 4 They also were heavier 15 years later than their peers who gained the recommended amount or less. 5 It was also found that new behaviors that began during pregnancy—specifically eating more calories, having three or more snacks a day, skipping lunch and doing less exercise—were continued after giving birth.

Weight Watchers Approach

Weight gain is an important part of a woman's prenatal medical care and is best managed by her physician. Weight Watchers does not provide any programs or services to women who are pregnant. However, achieving a healthy body weight prior to conception and then returning to that weight after giving birth is encouraged.

This content is reviewed regularly. Last updated April 28, 2011.

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1 Institute of Medicine. Weight Gain During Pregnancy: Reexamining the Guidelines. Washington, D.C.: National Academies Press, 2009.

2 Oken E, Taveras EMKleinman KP, Rich-Edwards JW, Gillman MW . Gestational weight gain and child adiposity at age 3 years. Am J Obstet Gynecol. 2007 Apr;196(4):322 e1-8.

2 Stotland NE, Haas JS, Brawarsky P, Jackson RA, Fuentes-Afflick E, Escobar GJ. Body mass index, provider advice, and target gestational weight gain. Obstet Gynecol. 2005 Mar;105(3):633-8.

3 Jain NJ, Denk CE, Kruse LK, Dandolu V. Maternal obesity: can pregnancy weight gain modify risk of selected adverse pregnancy outcomes? Am J Perinatol. 2007 May;24(5):291-8.

4 Linné Y, Rössner S. Interrelationships between weight development and weight retention in subsequent pregnancies: the SPAWN study. Acta Obstet Gynecol Scand. 2003 Apr;82(4):318-25.

5 Amorim AR, Rössner S, Neovius M, Lourenço PM, Linné Y.Obesity (Silver Spring). Does excess pregnancy weight gain constitute a major risk for increasing long-term BMI? 2007 May;15(5):1278-86.