Fifteen Years Later: Adolescent Mothers Weigh More But Their Babies Do Not (1990 To 2005)

American adolescents are bigger and more likely to be overweight or obese than they were two decades ago. Adult mothers and their infants have also gotten bigger. The purpose of this study was to determine if the size of pregnant adolescents and the size and maturity of their infants has changed. A racially/ethnically diverse group of 1187 13-through-18 year old primigravida participants in an adolescent-oriented maternity program was enrolled consecutively between 1990 and 2005 and grouped by year of conception. Maternal outcomes were: self-reported preconception weight measured height body mass index (BMI; weight/height/2) and the proportion of under average and overweight/obese adolescents. Infant outcomes were: birth weight gestational age and the proportion of small average and large for gestational age and preterm births. Covariates included: age race/ethnicity smoking pregnancy induced hypertension (PIH) abnormal glucose screen Caesarian delivery labor induction and infant sex. The analysis used ANOVAs/MANOVAs. The ANOVAs revealed a significant increase in maternal weight (p = 0.006) BMI (p = 0.002) overweight/ obese status (p less than 0.0001) age (p less than 0.0001) Hispanic ethnicity (p less than 0.0001) and induced labors (p = 0.004) over the study period. There was also a significant decrease in maternal height (p less than 0.0001) PIH (p = 0.01) and Caucasian adolescents (p less than 0.0001). None of the infant outcome measures or other covariates changed significantly over the 15 years. Following adjustment for significant covariates (age and race/ ethnicity) the increase in maternal weight and decrease in height remained statistically significant (p = 0.04 and 0.01 respectively). None of the other maternal or infant outcome measures changed significantly. The weight of adolescent mothers has increased over the past 15 years but neither the weight of their infants nor the proportion of small-for-gestational age and preterm births has changed. The findings arereminiscent of the results of studies demonstrating that adolescents give birth to smaller infants than same-sized adults and transfer less of the weight they gain during gestation to their fetuses. (authors)