New study links prenatal cocaine exposure to engaging in sex by age 15

Since 1994, researchers at Case Western Reserve University have studied mothers—some who used cocaine while pregnant and others who did not—to understand how the drug affected their children’s cognitive and social development. Their latest findings suggest a link between prenatal cocaine exposure and an adolescent’s likelihood to have sexual intercourse before age 15. Teens who were prenatally cocaine exposed (PCE) were 2.2 times more likely to engage in sexual intercourse before age 15 than those who weren’t, yet how PCE affects early sexual behavior may differ by gender, said lead researcher Meeyoung O. Min, assistant research professor of social work at the Jack, Joseph and Morton Mandel School of Applied Social Sciences. The research team’s findings are reported in a Drug and Alcohol Dependence article, “Effects of Prenatal Cocaine Exposure on Early Sexual Behavior: Gender Differences in Externalizing Behavior as a Mediator.” The article is online at dx.doi.org/10.1016/j.drugalcdep.2015.06.009. The new study focused on sexual activities of 354 adolescents (180 who were prenatally exposed to cocaine and 174 who weren’t). Researchers tested the children at 6, 12 and 18 months, and at ages 2, 4, 6, 9 through 12, and 15. (The National Institute on Drug Abuse, which funded the study, will continue supporting the project as researchers follow the teens into their 20s.) The researchers found that:

• Compared to 23 percent of non-cocaine exposed (NCE) teenagers, 29 percent of prenatally cocaine exposed (PCE) teenagers living in foster/adoptive care and 42 percent of PCE teenagers living with their birth mothers or blood-related relatives reported having sexual intercourse before age 15.
• Cocaine-exposed teenage girls who reported having behavior problems during their preteen years were more likely to have early sexual intercourse.
• 64 youth (or 18 percent; 37 PCE and 27 NCE) reported having sex as young as 13.
• Levels of lead in the blood during preschool years also were related to a greater likelihood of early sexual intercourse.
• Greater parental monitoring decreased the likelihood of early sexual intercourse, while exposure to violence increased the risk.

Why it matters

Data from the 2006–2010 National Survey of Family Growth indicated that 14 percent of females and 18 percent of males had sexual intercourse by their 15th birthday. Early sexual engagement has been associated with an increased risk of unintended teen pregnancies and sexually transmitted infections, including HIV. Substantial research has documented that childhood behavior problems (aggression, antisocial behavior, delinquency) may be a precursor of sexual engagement at an early age.

Addressing the problem

Prenatal cocaine exposure is related to early sexual intercourse, and externalizing behavior problems mediated the PCE effects in female adolescents. Interventions targeting externalizing behavior may reduce early sexual initiation and thereby reduce HIV risk behaviors and early, unplanned pregnancy in girls with PCE, the researchers suggest. In particular, they urge, interventions focusing on strengthening parental monitoring and decreasing violence and lead exposure may help reduce early sexual initiation among high-risk prenatally cocaine exposed adolescents. Interventions targeting externalizing behavior in girls may decrease early sexual behavior and promote sexual health. Contributors from the social work school at Case Western Reserve were: Sonia Minnes, associate professor and director of Project Newborn; Adelaide Lang, research project coordinator; and Susan Yoon, doctoral student. Also contributing to the article was Lynn Singer, deputy provost, professor of pediatrics and founding director of Project Newborn.