Teens who take a sexual abstinence pledge delay their sexual debut for a few years, but they have just as many sexually transmitted infections as nonpledgers, probably because they are more likely to engage in noncoital sex and aren't as likely to use a condom during any sexual activity.
Hannah Brückner, Ph.D., and Peter Bearman, Ph.D., said their findings might put a new spin on programs that stress abstinence as the only way to avoid STDs and pregnancy. “The all-or-nothing approach … may create additional barriers to knowledge and protection for adolescents. For example, the emphasis on virginity may encourage adolescents to limit their sexual activity to noncoital behaviors, which may nevertheless expose them to risks of infection” (J. Adolesc. Health 2005;36:271-8).
Health care behavior by pledgers further complicates the problem, they noted. “It is important to know that pledgers are less likely than nonpledgers to be tested for STDs and to have ever seen a doctor because they are worried about an STD,” said the investigators of Yale University, New Haven, Conn., and Columbia University, New York.
The researchers extracted data gathered from 2001 to 2002, during the third wave of the National Longitudinal Study of Adolescent Health. During this wave, respondents were age 18-24 years. A total of 11,471 respondents provided urine samples for STD testing (chlamydia, gonorrhea, and trichomoniasis). An additional 3,317 sexually active female respondents were randomly selected for human papilloma virus (HPV) testing.
Pledge status was collected from all three waves of the survey. Nonpledgers reported no abstinence pledge during any of the waves. Consistent pledgers reported pledging during all waves or pledging for the first time during wave 3. Inconsistent pledgers reported pledging during an early wave but not a subsequent wave.
Most of the group (80%) were nonpledgers. Only 7% were consistent pledgers; 13% were inconsistent pledgers.
Consistent and inconsistent pledgers delayed their time to first coitus by several years, compared with nonpledgers. Among nonpledgers, 75% reported first intercourse by age 18. Inconsistent pledgers reached the 75th percentile by age 20, and consistent pledgers by age 24.
Male pledgers delayed intercourse the longest. By age 25, 25% of consistent male pledgers were still virgins, compared with 15% of inconsistent pledgers and 7% of nonpledgers. By age 25, 21% of female consistent pledgers were still virgins, compared with 10% of inconsistent pledgers and 6% of nonpledgers.
Delaying first intercourse had no significant effect on STD incidence in the groups, however.
About 6.9% of nonpledgers, 6.4% of inconsistent pledgers, and 4.6% of the consistent pledgers tested positive for trichomoniasis, chlamydia, and/or gonorrhea.
For HPV infection, the rates were 26.5% among nonpledgers, 28.5% among inconsistent pledgers, and 26.7% among consistent pledgers.
Pledgers did have fewer sexual partners than nonpledgers (average of 1.5 partners vs. 2.4 partners), and were not exposed as long to STD risk. However, they were more likely to engage in noncoital sexual contact.
About 3% of respondents reported oral sex but no vaginal sex. About 2% of nonpledgers fell into that group, compared with 13% of consistent pledgers and 5% of inconsistent pledgers. About 0.7% of nonpledgers reported anal sex but not vaginal sex, compared with 1.2% of pledgers.
About 1% of male nonpledgers reported anal, but not vaginal, sex, compared with 3% of male inconsistent pledgers and 4% of male consistent pledgers.
Condom use during these experiences was very low for all respondents: Only 4% reported using a condom during oral sex, and about 30% reported using one for anal sex.
“The combination of low condom use and overrepresentation of pledgers [in noncoital sex] provides some support for the hypothesis that this behavioral pattern is associated with greater than expected STD acquisition among pledgers, although the numbers are small and provide an insufficient basis from which to make inference,” the authors said.