Recent research published in the Journal of Adolescent Health, discovered that teenage girls who are close to their moms are more likely to stay virgins. The key for parents, experts say, is not just talking with their daughters about sex, but being deeply involved in their children's lives.

The research, based on interviews with mothers and their 14- and 15-year-old girls, found that when families have meals together, when parents know where their children are, and when they know their kids' friends, it is less likely that a teenager will have sex. They found that mothers whose daughters were still virgins shared several qualities: the mothers strongly disapproved of their daughters having sex; they were satisfied with their relationship with their daughters; and they frequently talked with the parents of their daughters' friends.

Other factors made no difference in teen sex, including how religious the mothers were, how often they talked about sex with their daughters, or how uncomfortable they were talking about sex. Talking about birth control also did not appear to have any effect on teens' sexual behavior.