Predicting age of sexual debut in adolescent girls

OBJECTIVE: To examine the association between biologic, demographic, and family context variables and the age of initiation of intercourse among adolescent girls. METHODS: Data were analyzed from a longitudinal study of girls recruited from an urban adolescent medicine clinic. At intake, all subjects received the Kaufman Brief Intelligence Test, to establish a screening IQ score. Mothersʹ highest level of education and age when she had her first child were recorded. Parental monitoring (direct, with peers, and indirect) and the Family Environment Scale were utilized to assess the social environment. Subjects were asked the age of first consensual intercourse, and categorized as early (14 or less), average (15-16) and later (17 or older). The relationship of age of debut with demographic and family context variables was analyzed using a logistic regression. RESULTS: At intake the 174 subjects had a mean age of 14.5 years. 127 were known to be sexually experienced by the end of the study; 22% initiated younger than 15, 62% between ages 15-16, and 16% ages 17 or older. An additional 22 were seen at age 17 or older and reported they were not sexually active. This latter group was included in the “later” initiators. The final logistic model revealed that girls who reported their families were more expressive, had a greater moral religious emphasis, had more direct monitoring, and whose mothers had greater education, were older when they initiated intercourse. CONCLUSIONS: Developmental and contextual factors made important contributions to age of initiation of intercourse in this longitudinal study. Factors that are modifiable, such as parental monitoring and communication, should prove to be an effective target for intervention in protecting the adolescent from early engagement in high risk behaviors.