Adolescent body mass index as a strong predictor of pre-pregnancy obesity in Arkansas mothers.

Maternal obesity is strongly associated with adverse pregnancy outcomes. However, the extent to which adolescent weight status can predict pre-pregnancy obesity and severe obesity among future first-time mothers has not been well explored. This cohort study utilized adolescent body mass index (BMI) assessments linked to birth records for women 20-30 years old to examine this relationship. The population-based study cohort included 27,370 first-time mothers who had a 10th-grade BMI measurement; among this cohort, 18,881 had BMI assessments in 10th, 8th, and 6th grade. Most women who had severe obesity in 10th grade still had severe obesity prior to their first pregnancy (78.2%). Predictive characteristics using 10th-grade weight categories for predicting pre-pregnancy obesity and severe obesity combined achieved an area under the curve (AUC) of 84.2%, with 79.1% accuracy, 74.3% sensitivity, and 81.4% specificity. For pre-pregnancy severe obesity alone, the approach yielded an AUC of 88.1%, accuracy of 86.9%, sensitivity of 65.7%, and specificity of 91.0%. Predictive accuracy declined minimally in earlier grades (8th and 6th). Adolescent weight status demonstrates predictive capacity for pre-pregnancy obesity and severe obesity, even as early as 6th grade. Early risk identification may enable interventions to reduce maternal obesity and improve pregnancy outcomes.