Adolescent Pregnancies

Abstract

INTRODUCTION: Fetal growth restriction (FGR) is a significant contributor to neonatal mortality and morbidity, failure to grow, slow cognitive development, and chronic diseases in adulthood. Young maternal age is a risk factor for FGR. This study examines the contribution of adolescent pregnancy and gestational weight gain to FGR risk. METHODS: This was a population-based cohort of Ohio births (2006–2012), N=1,034,552. Analyses were limited to primiparous women with singleton, nonanomalous live births and data on body mass index (BMI, calculated as weight (kg)/[height (m)]2) and gestational weight gain (n=346,635). Gestational weight gain, categorized by Institute of Medicine recommendations, was stratified by maternal age (younger than 15, 15–17, 18–19, 20–34 years) and prepregnancy BMI. Logistic regression estimated the effect of young age, gestational weight gain, and BMI on FGR after adjustment for confounding factors. Adolescent-specific BMI was used for mothers younger than 19 years. RESULTS: Mean BMI was lower in adolescents (23.2–24.4) compared with older mothers (25.9). Adolescents were at higher risk for inadequate gestational weight gain (adjusted odds ratio [OR] 1.3–1.4, 95% confidence interval 1.2–1.7) despite adjustment for confounders, but they were not at increased risk for excessive gestational weight gain. Adolescents had higher odds of FGR in most BMI and gestational weight gain categories (OR range 1.17–1.59). However, this risk was attributed mostly to confounding effects; risks became nonsignificant after adjustment for race, low socioeconomic status, and tobacco use. Weight loss and inadequate gestational weight gain increased FGR risk, and excessive gestational weight gain was protective for FGR in all maternal age groups. CONCLUSION: Prepregnancy BMI and gestational weight gain are more influential on FGR risk than is young maternal age. Interventions should be aimed to improve rates of adolescents and women achieving appropriate gestational weight gain across all age groups.