Periconceptional Risk Factors for Birth Defects among Younger and Older Teen Mothers

Abstract

Study objectives: We sought to determine whether selected periconceptional health behaviors that influence risk for birth defects differ between older and younger adolescents and whether pregnancy intention predicts more positive preconception health behaviors among teens.

Design and participants: We analyzed interview responses from 954 adolescent control group participants from the National Birth Defects Prevention Study who delivered live infants during 1997-2007.

Main outcome measures: Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated for factors of interest by age categories (13-15, 16-17, and 18 years, relative to 19 years). To construct a composite periconceptional behavior index, we summed the following healthy behaviors: nonsmoker, nondrinker, folic acid supplementation, and eating 5 or more servings of fruits and vegetables per day.

Results: Analyses indicated that women in the youngest group (13-15 years of age) were more likely to be Hispanic (aOR 2.83, 95% CI 1.40-5.70) and less likely to engage in some unhealthy pregnancy-related behaviors compared with 19-year-olds, such as smoking (aOR 0.45, 95% CI 0.20-0.99) and being overweight or obese (aOR 0.32, 95% CI 0.16-0.61). However, they were also less likely to have taken periconceptional folic acid (aOR 0.44, 95% CI 0.21-0.90). About one-third of teen mothers indicated that their pregnancies had been intended. Among 18- and 19-year-olds, this predicted a higher mean value for the composite periconceptional behavior index (2.30 versus 1.94, P ≤ .01).

Conclusions: Teen mothers are not a homogeneous group. Each age subgroup presents varied demographic and behavioral factors that put them at varying levels of risk for birth defects. Furthermore, caregivers should not assume that teens do not plan pregnancies or that they need not be informed of the importance of periconceptional health.

Keywords: Adolescent; Adolescent behavior; Congenital anomalies; Drinking behavior; Folic acid; Fruit; Health behavior; Health surveys; Preconception care; Tobacco use; Vegetables.