Living in a weight conscious world, women are justifiably concerned about gaining weight throughout pregnancy. Am I gaining too much? Am I gaining too little weight for my baby? Why does my facebook friend have a much bigger bump than I do at the same gestational age? These obviously valid questions and concerns deserve to be addressed, so let’s take a brief look at weight gain during pregnancy.
This is an important issue for many reasons. Studies show that excessive weight gain during pregnancy is more difficult to lose postpartum. In addition, excessive pregnancy weight puts infants at risk for increased birth weight. Emerging evidence indicates the occurrence of infant weight pre-programming in the womb. In other words, a woman who gains too much weight during pregnancy or who is diabetic, is placing her child at increased risk of obesity and diabetes later in the child’s life. On the other side of the coin women gaining inadequate weight produces risks of its own such as infants with decreased birth weight.
These concerns prompted several organizations to publish recommended guidelines for appropriate weight gain based on an individual’s pre-pregnancy weight. These guidelines are slightly altered to take into account women carrying twins. I do think it is important to note there is debate among physicians that the following weights err on the high side, but they are currently considered a safe guideline.
For women with a singleton the total gain during pregnancy is as follows:
|Prepregnancy Weight Category||Body Mass Index*||Recommended Range of Total Weight (lb)||Recommended Rates of Weight Gain† in the Second and Third Trimesters (lb) (Mean Range [lb/wk])|
|Underweight||Less than 18.5||28–40||1 (1–1.3)|
|Normal Weight||18.5–24.9||25–35||1 (0.8–1)|
|Obese (includes all classes)||30 and greater||11–20||0.5 (0.4–0.6)|
|*Body mass index is calculated as weight in kilograms divided by height in meters squared or as weight in pounds multiplied by 703 divided by height in inches. †Calculations assume a 1.1–4.4 lb weight gain in the first trimester. Modified from Institute of Medicine (US). Weight gain during pregnancy: reexamining the guidelines. Washington, DC. National Academies Press; 2009. ©2009 National Academy of Sciences.|
For women carrying twins the recommended weight gain is 37-45lb for normal weight women, 31-50lb for overweight women and 25-42lb for obese women. Weight gain for twins is not determined for underweight women.
As always, if you have concerns about any of these issues please schedule an appointment to see your physician.