How accurately do pregnant adolescents estimate their weight prior to pregnancy?

An accurate determination of maternal prepregnancy weight (PPW) is critical because it is used to calculate weight gain during pregnancy and is one of the best correlates of infant birthweight. The PPW recorded in the prenatal record is usually obtained as part of the patient's history. This study compares PPWs reported by a group of 76 adolescent women (stated weight) with actual weights taken and recorded in medical and school health records by health professionals prior to conception. Simple correlations and a linear regression were used for data analysis. A highly significant correlation (0.98) was found between the stated and actual PPW. Overweight girls tended to underestimate their PPW. These findings suggest that the PPW estimates by adolescents with an identifiable source of medical care are accurate enough to be used to estimate weight gain during pregnancy.