Sustained weight gain after pregnancy is a concern for adolescents who may be entering adulthood at an unhealthy weight. We studied the association between pre-pregnancy body mass index (BMI), gestational weight gain (GWG), and post-pregnancy BMI in adolescent pregnancies.
In a longitudinal follow-up of an adolescent pregnancy study cohort, self-reported pre-pregnancy weight, measured delivery weight, and post-pregnancy weights were abstracted from the medical record. BMI and GWG were compared using t-tests and linear regression.
Among 91 adolescents, mean pre-pregnancy BMI was 24.6 (SD 5.7) and mean GWG was 34.1 lbs (SD 13.8). Three were underweight, 55 were normal weight, 22 were overweight, and 11 were obese before their first pregnancy. While GWG increased with increasing pre-pregnancy BMI for underweight (mean 28 lb gain), normal weight (34 lb), and overweight (38 lb) teens, obese teens had the lowest GWG (27 lb). Among 42 teens with post-pregnancy weight data within 4 years of their first delivery, mean post-pregnancy BMI was 26.3 (SD 5.0) with an average BMI increase of 2.0 points (SD 5.1) (P=.013) from pre-pregnancy. Within 4 years of their first delivery, 19 teens moved to a higher BMI category, 18 remained in the same BMI category, and 5 moved to a lower BMI category. For every 10 lb increase in GWG, BMI within 4 years increased on average by 1.6 points (P=.006).
Adolescent mothers are at risk for developing and maintaining unhealthy BMI, which may be amplified by GWG.
Women & Infants Hospital, Providence, RI
Financial Disclosure: The authors did not report any potential conflicts of interest.