Evidence does not support the effectiveness of abstinence-only sex education.[2][3] It has been found to be ineffective in decreasing HIV risk in the developed world.[4] It does not decrease rates of sexual activity or unplanned pregnancy when compared to comprehensive sex education.[2]
The topic of abstinence-only education is controversial in the United States, with proponents claiming that comprehensive sex education encourages premarital sexual activity, and critics arguing that abstinence-only education is religiously motivated and that the approach has been proven ineffective and even detrimental to its own aims.
^Underhill, Kristen; Operario, Don; Montgomery, Paul (2007). "Abstinence-only programs for HIV infection prevention in high-income countries". Cochrane Database of Systematic Reviews (4): CD005421. doi:10.1002/14651858.CD005421.pub2. PMID17943855.