News Release

Media briefing note: Dr. Carol A. Ford, this study’s lead author, will participate in a news briefing conference call at 10 a.m. Tuesday (July 5). Details are at the end of the release.

Adolescent girls perceiving parental disapproval of sex
are less likely to have STIs as young adults: study

BY TOM HUGHES
UNC School of Medicine

CHAPEL HILL -- Adolescent girls who perceive their parents disapprove of them having sexual intercourse are less likely to have sexually transmitted infections as young adults than girls without such perceptions, a study led by University of North Carolina at Chapel Hill researchers has concluded.

Perceptions of parental disapproval did not have a similar effect among adolescent boys, the study found.

Furthermore, researchers reported that most factors associated with increased duration of virginity in adolescence have no effect on an adolescent’s likelihood of having sexually transmitted infections six years later.

"To our knowledge, this is the first study to find a link between adolescents’ perceptions of parental opinions about sex and the chance that they have a sexually transmitted infection in young adulthood," said Dr. Carol A. Ford, lead author of the study, published in the July issue of the Archives of Pediatric & Adolescent Medicine.

Ford is associate professor in the departments of pediatrics and medicine in UNC’s School of Medicine.

The researchers arrived at these conclusions after analyzing data obtained by conducting in-home interviews and collecting urine samples from individuals who participated in the National Longitudinal Study of Adolescent Health (Add Health).

Add Health is believed to be the largest, most comprehensive survey of adolescents ever undertaken. It began in 1994 with a grant from the National Institute of Child Health and Human Development, with co-funding from 17 other federal agencies. Dr. Kathleen Mullan Harris, Gillian T. Cell distinguished professor of sociology in UNC’s College of Arts and Sciences and a fellow of UNC’s Carolina Population Center, directs the study.

Participants were originally interviewed for Add Health in 1995, when they were in grades seven through 12. Six years later, interviews were conducted with 14,322, or 75.7 percent, of the original participants.

In addition, urine samples from 11,594, or 81 percent, of the original participants were tested for the sexually transmitted diseases chlamydia, gonorrhea and trichomoniasis. Overall, 6.2 percent of these respondents tested positive for at least one of the three diseases.

Researchers examined if a wide range of adolescent factors predicted a likelihood of having a sexually transmitted infection six years later in young adulthood. These included family variables such as perceived parental disapproval of sex and contraception, school variables such as feelings of connectedness to school and if the respondent attended a parochial school, and individual variables such as grade point average and if the respondent had made a virginity pledge.

Results include findings that:

Adolescents with higher grades were less likely to have acquired sexually transmitted infections six years after the original study than those with lower grades.

Girls who perceived that their parents disapproved of them having sex as adolescents were less likely to have sexually transmitted infections six years later, but this was not true for boys.

Most family, school and individual factors linked to delaying the start of sexual activity among adolescents had no effect on the respondents’ likelihood of having sexually transmitted infections six years later.

"Our results suggest that effective communication between adolescents and their parents about sex is important," Ford said. "Parents who do not approve of their adolescents having sex during adolescence should try to effectively communicate this."

Results also showed that curable sexually transmitted infections are common among young adults. Researchers studied factors that are associated with delay of sex among adolescents and found that – in large part – they did not decrease risk for sexually transmitted infections in young adulthood.

These results highlight two things, Ford said. First, sexually transmitted infections are complex biological outcomes. Second, it is important to think of adolescence and young adulthood within a developmental framework.

"We know that strategies that effectively delay onset of sex among adolescents should reduce rates of sexually transmitted infection among adolescents – because fewer adolescents will be having sex," she said. "We also know that adolescents who have sex are at risk of sexually transmitted infection."

The research team published a paper in the American Journal of Epidemiology in April that concluded that the earlier the start of sexual intercourse, the greater the risk of later sexually transmitted infections. But this link dissipates over time, Ford said.

"Among 24-year-olds, the odds of having a sexually transmitted infection was the same whether sex was initiated at age 13 or 17," she said. "Efforts to reduce rates of sexually transmitted infections among adolescents and young adults should consider these nuances."

Besides Ford, UNC authors of the study were Brian Wells Pence, a doctoral student in epidemiology in the School of Public Health; Dr. William C. Miller, an assistant professor of infectious diseases in the School of Medicine and of epidemiology in the School of Public Health; and Dr. Myron Cohen, J. Herbert Bate professor in the schools of medicine and public health, chief of the division of infectious diseases in the School of Medicine and director of the UNC Center for Infectious Diseases.

Other authors were Drs. Michael D. Resnick, Linda H. Bearringer and Sandy Pettingell, all from the University of Minnesota at Minneapolis.

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Note: Media representatives interested in participating in a July 5 media briefing conference call with Ford are asked to call (919) 962-2741 at 10 a.m. The conference call will last an hour. To request an interview with Ford, call Stephanie Crayton at (919) 966-2860 or scrayton@unch.unc.edu.

UNC School of Medicine contact: Stephanie Crayton, (919) 966-2860 or scrayton@unch.unc.edu