Teenage girls who are sexually active tend to have a male partner close to their own age, rather than one many years older than themselves. However, young women who have a male partner who is much older (6 years or more) are at greater risk for unintended pregnancies.

A new report in Family Planning Perspectives shows:

• Sixty-four percent of sexually active women ages 15 to 17 have a partner within two years of their own age.

• Twenty-nine percent have a partner three to five years older.

• Just 7 percent have a partner six years or more older, but they accounted for 19 percent of teen pregnancies.

• One reason for the higher pregnancy rate is that about 78 percent of teens with a male partner close to their age used contraceptives compared with only 66 percent of women with an older partner.

Why do teenage girls involved with older men get pregnant more frequently? Among the factors suggested by researchers:

• Older men may expect the woman to take responsibility for contraception.

• Teenage women are not as likely to use birth control pills as women a few years older.

• Teens may want to become "adults" more quickly to escape an unhappy or deprived home environment.

• An older man may be better able to care for a family than a teenager.

Another factor influencing teens may be sex education. According to a recent article in the Journal of Political Economy, "[t]he evidence suggests that sex education had some causal influence on teen sexual behavior in that it altered the risks of sexual activity." Researchers found that sex education for women was associated with earlier initial sexual activity and was also slightly associated with earlier pregnancy for some groups.

Source: Jacqueline Darroch et al., "Age Differences Between Sexual Partners in the United States," Family Planning Perspectives, July/August 1999, Alan Guttmacher Institute; Gerald S. Oettinger, "The Effects of Sex Education on Teen Sexual Activity and Teen Pregnancy," Journal of Political Economy, June 1999.