Board of the IOM and the Board on Children, Youth, and Families in the Division of Behavioral and Social Sciences and Education of the National Research Council to review the IOM (1990) recommendations for weight gain during pregnancy. Specifically, the committee was asked to review evidence on relationships between weight gain patterns before, during, and after pregnancy and maternal and child health outcomes; consider factors within a life-stage framework associated with outcomes such as lactation performance, postpartum weight retention, and cardiovascular and other chronic diseases; and recommend revisions to existing guidelines where necessary. Finally, the committee was asked to recommend ways to encourage the adoption of the weight gain guidelines through consumer education, strategies to assist practitioners, and public health strategies.


The new guidelines for GWG that are shown in Table S-1 are formulated as a range for each category of prepregnancy BMI. This approach reflects the imprecision of the estimates on which the recommendations are based, the reality that good outcomes are achieved within a range of weight gains, and the many additional factors that may need to be considered for an individual woman. It is important to note that these guidelines are intended for use among women in the United States. They may be applicable to women in other developed countries. However, they are not intended for use in areas of the world where women are substantially shorter or thinner than American women or where adequate obstetric services are unavailable.

The new guidelines differ from those issued in 1990 in two ways. First, they are based on the World Health Organization (WHO) cutoff points for the BMI categories instead of the previous ones, which were based on

TABLE S-1 New Recommendations for Total and Rate of Weight Gain During Pregnancy, by Prepregnancy BMI

Prepregnancy BMI

Total Weight Gain

Rates of Weight Gain* 2nd and 3rd Trimester

Range in kg

Range in lbs

Mean (range) in kg/week

Mean (range) in lbs/week

Underweight (< 18.5 kg/m2)



0.51 (0.44-0.58)

1 (1-1.3)

Normal weight (18.5-24.9 kg/m2)



0.42 (0.35-0.50)

1 (0.8-1)

Overweight (25.0-29.9 kg/m2)



0.28 (0.23-0.33)

0.6 (0.5-0.7)

Obese (≥ 30.0 kg/m2)



0.22 (0.17-0.27)

0.5 (0.4-0.6)

* Calculations assume a 0.5-2 kg (1.1-4.4 lbs) weight gain in the first trimester (based on Siega-Riz et al., 1994; Abrams et al., 1995; Carmichael et al., 1997).

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