Age of first intercourse and risk of sexually transmitted disease

Study Objective: This study examines the risk of acquisition of multiple episodes of a sexually transmitted disease (STD) as it relates to age of first intercourse and sexual behaviors among high risk adolescent females.

Design: A linear regression model was used to predict number of STD episodes. The relationship between number of STDs and age at first intercourse was also examined with a contingency table.

Setting: Sexually active female adolescents (n = 248) from an urban primary care adolescent clinic were interviewed regarding sexual behaviors by a female research assistant.

Participants: The girls ranged in age from 12 to 21 (mean = 16.9 years); 80% were African-American and 20% were caucasian. The age of first intercourse ranged from 10 to 18. Seventy-four percent of the girls had a history of an STD.

Results: In the final regression mode (adjusted R² = 0.28), a higher number of episodes of STD was significantly related to having a younger age of first intercourse (p < 0.05), more lifetime partners (p < 0.01), and a longer time since first intercourse (p < 0.01). A 4 × 3 contingency table of age of first intercourse and history of STD revealed that those adolescents who are under 13 years when they initiate intercourse are at significantly higher risk for acquiring STD, and those that are 17 and older are at significantly lower risk (chi-square = 25.11, p < 0.01).

Conclusions: These findings are discussed in relation to behavioral risk factors and interventions which aid girls to postpone sexual involvement to the later teen years.