Both the timing and the type of sexual abuse during childhood and adolescence are associated with women’s increased risk of early pregnancy.1 Among young women in Arizona, those who experienced sexual abuse in childhood, in adolescence or in both developmental periods were at increased risk of pregnancy before age 22, compared with women who had no history of sexual abuse (hazard ratios, 1.2–1.8). Rape in childhood, in adolescence and in both childhood and adolescence were associated with an increased risk of early pregnancy (1.4–2.0). Associations between sexual abuse and early pregnancy were weakened when age at first intercourse was taken into account and varied by women’s educational attainment.
Researchers performed a secondary analysis of data from a 1997 survey to determine the associations between early pregnancy and the timing and severity of sexual abuse. In all, 1,790 women aged 18–22 participated, recruited from 44 urban and rural sites that included clinics, schools and social service agencies. The survey, available in English and Spanish, asked respondents about their sexual history, sexual risk behaviors, sexual abuse history and pregnancy history. History of sexual abuse was measured using an adapted version of a previously validated survey. Type of abuse was defined by the respondent’s report of the most severe form of abuse experienced: molestation (unwanted touching, fondling or exposure to sexual material), coercion (being pressured into having sex), attempted rape and rape. Analyses were conducted using Cox proportional hazard models.
Three-quarters of respondents had graduated from high school; two-thirds of their mothers had done so. Some 41% of participants were white; 13% were black, 27% were Latino, 16% were Native American and 3% reported another race or ethnicity. About three-quarters had ever experienced physical abuse or neglect, and half had ever been pregnant. Overall, 11% of women had experienced sexual abuse during childhood only (before age 12), 40% during adolescence only (at age 12 or older) and 19% during both periods; 31% had no history of sexual abuse. The most common forms of sexual abuse reported by those abused in childhood only and adolescence only were rape (26% and 34%, respectively) and molestation (63% and 33%, respectively); the most common among those abused in both childhood and adolescence was rape (64%). Age at first intercourse ranged from 14.1 years among those with a history of both childhood and adolescent sexual abuse to 16.1 years among those reporting no sexual abuse.
Unadjusted hazard ratios for early pregnancy were elevated among women with any history of abuse—in childhood, in adolescence or in both (hazard ratios, 1.1–1.8). The risk of early pregnancy was also elevated for those whose mothers had had less than a high school education and among those whose mothers’ educational attainment was unknown (2.1 and 2.4, respectively); among blacks, Latinos and Native Americans (1.7–2.5); among those with a history of physical abuse or neglect (1.4); and among those reporting rape as the most severe type of abuse experienced (1.8). Being a high school graduate and older age at first intercourse were associated with a lower risk of early pregnancy (0.3 and 0.8, respectively).
When ethnicity and participants’ and their mothers’ education levels were controlled for, women who experienced sexual abuse only in childhood had a 20% greater risk of early pregnancy than those with no history of sexual abuse (hazard ratio, 1.2), while those who had experienced sexual abuse only in adolescence had a 30% greater risk (1.3); women who had been sexually abused in both childhood and adolescence had an 80% greater risk of early pregnancy (1.8). Attempted rape and rape in both childhood and adolescence, attempted rape and rape in childhood, and rape in adolescence were all associated with an increased risk of pregnancy (1.4–2.0). A statistical test for mediation determined that sexual abuse was associated with an increased risk of earlier age at first intercourse, which, in turn, was associated with an increased risk of early pregnancy. When age at first intercourse was added to the model, only the association between early pregnancy and sexual abuse in both childhood and adolescence remained significant (1.4).
Finally, among women who had not graduated from high school, sexual abuse in childhood, in adolescence and in both were associated with an elevated risk of early pregnancy (hazard ratio, 1.4 for each). Among high school graduates, sexual abuse in childhood only or in adolescence only was not associated with early pregnancy, but abuse in both periods was associated with an elevated risk (2.0).
The researchers comment that this is the first study to examine pregnancy risk and timing of sexual abuse among an ethnically and geographically diverse sample using a validated measure of sexual abuse. They also acknowledge several limitations, including the study’s reliance on self-reported data, cross-sectional design, limited generalizability and lack of measures on frequency of sexual abuse. The researchers note that the study highlights "the importance of sexual abuse prevention to reduce pregnancy risk among adolescent women."—L. Melhado