The 131st Annual Meeting (November 15-19, 2003) of APHA

The 131st Annual Meeting (November 15-19, 2003) of APHA

5098.0: Wednesday, November 19, 2003 - 12:30 PM

Abstract #66337

Misclassification of prepregnancy body mass index and Institute of Medicine gestational weight gain recommendations among adolescents: Is it time for a revision?

Isabel Diana Fernandez, MD, MPH, PhD, Division of Epidemiology, Department of Community and Preventive Medicine, University of Rochester Medical School, 601 Elmwood Ave, Box 644, Rochester, NY 14642, 585-275-9554, diana_fernandez@urmc.rochester.edu

In 1990 the Institute of Medicine (IOM) recommended increases in gestational weight gain (GWG) to prevent intrauterine growth retardation (IUGR). The IOM assigned GWG ranges according to adult prepregnancy body mass index (BMI) cut-offs with the caveat that they might result in post-partum weight retention and obesity. Adolescents are at greater risk for IUGR and their overweight prevalence tripled in the past three decades. Studies on the epidemiology of GWG and its effects on birth outcomes among adolescents used IOM cut-offs to categorize prepregnancy BMI. Adult BMI cannot be used for adolescents given that BMI changes with age and, therefore, it would misclassify adolescents into pre-pregnancy BMI categories and their correspondent GWG ranges. We estimated the percent misclassification of BMI categories by comparing the IOM categories (low < 19.8, average = 19.8-26.0, high = 26.1-29.0, and very high >= 30.0) to the current CDC BMI-for-age percentile ones (underweight = < 5th Pc, adequate >= 5th - <85th Pc, at risk of overweight >=85th - <95th Pc, and overweight >= 95th Pc). Data on adolescents aged less than 20 were obtained from a population birth registry (n = 12608). Misclassification occurred in 23.50% of the sample, mainly among adolescents at risk of overweight (26.94 % and 13.50% were misclassified as very high and average, respectively) and of adequate BMI-for-age (23.40 % and 0.63% were misclassified as low and high, respectively). BMI-for-age percentiles should be used to avoid misclassification in studies involving GWG and to empirically derive GWG recommendations specifically for adolescents.

Learning Objectives:

Keywords: Adolescent Health, Pregnancy

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.

Maternal and Child Health Epidemiology

The 131st Annual Meeting (November 15-19, 2003) of APHA