There is an often-told joke in China about a seemingly intelligent couple - both university educated - who after months of trying for a child finally go to the doctor as a last resort when the woman is unable to get pregnant.

A little probing on the part of the doctor into the couple's sex life quickly reveals the problem - they don't have a sex life.

The joke is that the couple are under the impression that by simply lying in the same bed together, the man's sperm will miraculously "fly to the woman's nest" (a literal translation from the Chinese) without any physical interaction between them.

However, it appears that there are still couples who believe this is actually how conception occurs.

Zhang Rong, deputy director of the Maternity and Children's Healthcare Center situated in Putuo district, was quoted recently as saying she has lately dealt with a couple who believed exactly this.

So although to most people, this may be little more than a joke used to mock the more unworldly among us, the story has a serious message behind it. And that message is that sex education in China is being seriously neglected.

In China, most people are reluctant, and even ashamed, to talk about sex, and this is particularly true when it comes to parents and children. In China's feudal society many couples only learnt about sex through drawings surreptitiously hidden in the soles of embroidered shoes that were passed along with a bride's dowry.

What's sad is that things haven't moved on that much. When I was a junior high school student some 10 years ago, "sex education" was a part of our biology studies. In a small section at the end of a chapter in our textbooks, we were introduced to the reproductive organs complete with pictures. But just as I was hoping to learn about the practical application of these biological facts and body parts, our evidently flustered teacher quickly abandoned the subject, saying: "Don't worry - you won't be tested on this subject."

I think it would be a good idea if this subject WAS tested in subsequent exams. That way, teachers wouldn't be able to shirk their responsibilities because of embarrassment or out of a misplaced sense of modesty.

Of course the most vital part of sex education is not the act itself - but the issues of contraception and STDs (sexually-transmitted diseases). Every year 13 million abortions are carried out in China, and it's not unrealistic to point out that a large proportion of them would have been preventable if the women or men involved had used contraception.

Similarly, the incidence of STDs and AIDS are both on the rise in China and it is only through education that these problems can be fully addressed.

The time has come to stop burying our heads in the sand when it comes to sex. The ignorance of older generations is an unavoidable part of our past. But let's not visit this same ignorance on our own children.