But a new study finds, you shouldn't do it just once, but parents should consider having repeated discussions with their children about many aspects of sex.
The study in the journal Pediatrics finds parents who introduce new sexual topics, and then develop them through repeated discussions, have a greater influence. The more parents talked, the closer their relationships.
The report also cited earlier studies that showed children who were communicated with were more likely to delay intercourse and, if they chose to have sex, to use contraception and have fewer partners.
