Pre-Pregnancy Body Mass Index among Pregnant Adolescents: Gestational Weight Gain and Long-Term Post Partum Weight Retention

Abstract 

Study Objective

To determine the relationship between adolescents' pre-pregnancy body mass index (BMI), and gestational weight gain and postpartum weight retention.

Design

We review the medical records of adolescents participating in a prospective cohort study on comprehensive health care and parenting education to determine pre-pregnancy BMI, gestational weight gain, and postpartum weight retention at one year.

Setting

Urban academic hospital clinic.

Participants

102 pregnant adolescents aged 15–21 years.

Main Outcomes

Gestational weight gain and weight retention at one year postpartum.

Results and Conclusions

Fifty-two (51%) adolescent women had normal pre-pregnancy BMI according to the Institute of Medicine classification. Adolescent women with normal (36.5%) and high pre-pregnancy BMI (66.5%) were more likely than women with low pre-pregnancy BMI (26.5%) to exceed recommended gestational weight gain. Adolescent women who exceeded recommended weight gain retained significantly more weight at 1 year postpartum than women with weight gain within or below the recommendation. In a linear regression model that controlled for age, smoking, pregnancy complication, and post partum contraceptive use, pre-pregnancy BMI and gestational weight gain were the strongest predictors of postpartum weight retention at 1 year.

A normal to high pre-pregnancy BMI and excessive gestational weight gain are important predictors of postpartum weight retention in adolescents. These two predictors must be monitored systematically with the aim of preventing postpartum obesity and its associated diseases among this population.

Key Words: Pregnancy in adolescents, Body Mass Index, Gestational weight gain, Postpartum weight retention, Obesity