Weight gain in pregnancy and application of the 2009 IOM guidelines: Toward a uniform approach

OBJECTIVE: There is an urgent need to adopt standardized nomenclature as it relates to gestational weight gain (GWG), a more uniform approach to calculate it, and hence quantifying adherence to the 2009 Institute of Medicine (IOM) guidelines. METHODS: This perspective highlights the varying methods used to estimate GWG and discuss the advantages and limitations of each. RESULTS: While these calculations could be argued to have a minimal impact on data at the population level, on the patient level, incorrectly estimating weight at conception can result in misclassification of preconception body mass index (BMI) and assignment of the IOM guidelines which inherently affect the prospective management of weight gain (and potential outcomes) during the current pregnancy. CONCLUSIONS: This study recommends that preconception BMI and total GWG be determined objectively and total GWG be adjusted for length of gestation before assessing adherence to the IOM GWG guidelines.