Research suggesting a link between young women's substance use and their subsequent likelihood of having an abortion has led to the conclusion that reductions in substance use could help lower abortion rates. However, as Steven C. Martino and colleagues note in this issue of Perspectives on Sexual and Reproductive Health (see article), that conclusion rests on an incomplete understanding of the relationship between substance use and abortion. To improve that understanding, Martino and his team explored substance users' risk of abortion in longitudinal analyses that permitted them to assess whether any part of the risk was attributable to elevated levels of unplanned pregnancy among these women. In addition, the researchers took into account women's behavior and attitudes that mark them as unconventional with respect to their connectedness to family, school, and religious and social institutions.
The investigators found that use of marijuana during adolescence was directly associated with the likelihood of abortion in young adulthood, and that use of other substances had indirect associations, because it was related to unplanned pregnancy. However, unconventionality was a strong predictor of both abortion and unplanned pregnancy, and it explained some of the associations between substance use and these outcomes. The findings, Martino and colleagues write, "strongly support the notion that unconventional women are more likely to engage in risky behaviors...that put them at risk for unplanned pregnancy, and this in part explains the higher prevalence of abortion among [substance users}." Thus, the researchers conclude, reducing substance use is unlikely to result in lower levels of abortion.
Also In This Issue
•Several contributions in this issue look at young people's sexual risk, attitudes and behavior in innovative ways that could help lay the groundwork for new approaches to sexual health interventions and education.
Barbara VanOss Marín and colleagues (see article) show that among a sample of California youth followed through their middle school years, those who had had a boyfriend or girlfriend by seventh grade not only were more likely than others to be sexually active in ninth grade, but also had differed from others in ways that may affect sexual risk as early as sixth grade. Additionally, females (but not males) who had had an early relationship with someone as little as two years their senior were at increased risk of sexual activity later in middle school. The authors stress the need for parents and communities to discourage middle school youth from early romantic involvement.
Lisa D. Lieberman (see article) comments that Marín's finding of the relationship between early dating and sexual behavior provides "one of the missing pieces in both youth and parent interventions." Attention to this issue, as well as to the possible effect of even small age differences between young romantic partners, in Lieberman's view, should be incorporated into youth and parent interventions aimed at reducing young people's sexual risk.
Mary A. Ott and coauthors (see article) ask a question that is generally overlooked in research on adolescents' sexual risk perceptions: What motivates young people to have sex in the first place? For the ninth graders whom Ott and her colleagues studied, the answer is that they want a relationship to bring intimacy, social status and pleasure, and they believe that some of these goals will be fulfilled if they have sex. The researchers emphasize that programs and clinicians need to speak to youngsters at risk "in a language they understand, addressing the perceived benefits of sex as well as perceived risks."
Kelly Ladin L'Engle and her team (see article) posit that some teenagers are more "cognitively susceptible" to sexual initiation than others—they feel more ready to begin their sexual lives and consider it more likely that they will do so—and are therefore at greater risk. A scale constructed by the researchers enabled them to identify susceptible adolescents in a sample of seventh and eighth graders; these youth were more likely than their nonsusceptible peers to initiate intercourse during a two-year follow-up period. Adolescents who are committed to postponing sexual involvement and those who are susceptible to sexual initiation need different kinds of sexual health messages and interventions; the ability to distinguish these groups "would be very helpful in intervention efforts."
Finally, John S. Santelli and colleagues (see article) document that nationwide, sexually active high school students' contraceptive use is improving, and their pregnancy risk is declining. Nevertheless, nearly half of pregnancies among these young people occur because of nonuse of contraceptives; slightly more than half are attributable to contraceptive failures. It is crucial, the authors stress, that programs tailor messages to young people's needs, encouraging nonusers to practice contraception and ensuring that those already doing so use their methods correctly and consistently.
•Fifty-one unintended pregnancies occurred for every 1,000 U.S. women of reproductive age in 2001, but as Lawrence B. Finer and Stanley K. Henshaw show (page 90), the rate was considerably above average among certain subgroups—particularly young adults, cohabiting women, poor women, and members of racial and ethnic minorities. Furthermore, the disparity between rates of the poorest and wealthiest women increased between 1994 and 2001. The authors call for programmatic and policy efforts that "help women plan pregnancies through the use of well-suited and effective contraceptive methods."