'Waiting until marriage is a sensible choice for your son or daughter to make when it comes to sex," says a government Web site on abstinence and teen sex.

I agree that abstinence until marriage is the right choice for some people. You can save yourself from the risk of HIV and unwanted pregnancy. But what if you don't meet the right person until you're 27, or 32, or 41? What if you never have the opportunity to get married? What if you're gay?

The government offers no advice on when to start having sex, and the joys that go with it, if you don't marry.

A new paper in this month's American Journal of Public Health finally addresses the pros and cons of starting sex at various ages. It doesn't give a final answer, but at least it broaches an important topic.

"It's very easy to ridicule abstinence policies," said lead author Theo Sandfort of Columbia University's HIV Center for Clinical and Behavioral Studies. "But what do we actually know, and when do we tell kids as to when to start or not?"

In their search for answers, Sandfort and his colleagues looked at data from the National Sexual Health Survey, which in the 1990s polled more than 8,000 adults 18 and up and asked them a variety of questions about their sex lives, as well as their physical and sexual health.

He divided the subjects into three groups depending on the age at which they had sexual intercourse compared with others of the same gender and ethnic group. Overall, the average age for starting sex was then 17.5. So the early starters generally had intercourse around 14, the late group starting closer to 22.

Sandfort found that when people started having sex mattered. It was connected to all sorts of health factors, but later wasn't necessarily better.

"The normative starters were the best off," he said, referring to those who were about average compared with their peers. Early starters had a higher incidence of STDs and were more likely to suffer later marital and sexual problems. But the late starters had problems too, particularly the men, who suffered disproportionately from erectile dysfunction or failure to get aroused.

Sandfort said the study could not distinguish cause and effect. There's no evidence that starting sex late causes problems. More likely, men who have low sex drive or erection trouble avoid sex longer. But neither did the study find any particular harm in starting sex at a typical age of around 17.

To find out what the government's abstinence-only educators tell their kids, I talked with Kenneth J. Wolfe, a spokesman for the Family and Youth Services Bureau, part of the Department of Health and Human Services. He would not answer my questions on the record, but he did not dispel my understanding that abstinence education recommends abstinence until marriage, whenever that might happen.

I'm glad I was not taught that way, because it wouldn't have helped me to successfully abstain from sex as a teen, which I did and which I'm glad I did. Teenage girls have enough problems without having to sweat out pregnancy tests or contemplate the possibility of STDs.

My parents persuaded me to hold off for the sake of my future, which they said held the possibility of achievement and adventure and men far more interesting and intelligent than any teenage boys I could hope to find in high school. My teachers gave me the basics on birth control, which came in handy later.

It wasn't about waiting years or even decades for a marriage that might never happen. It was about waiting until adulthood, which was just around the corner. Some of us need to see a little light at the end of the tunnel.

Contact staff writer Faye Flam at 215-854-4977 or fflam@phillynews.com.