By Megan Lane BBC News Online Magazine

Parents-to-be have always been curious about the sex of their child. When we found out I was pregnant, the first thought that crossed our minds - along with "I hope it's healthy" and "please, not twins" - was "boy or girl?"

Some wait for the answer in the delivery room; others ask at the routine scan halfway through a pregnancy. But as standard-issue NHS monitors provide a somewhat grainy black-and-white image, this may be an educated guess at best. The umbilical cord, for instance, may dangle in such a way that it is mistaken for, er, tickle-tackle.

New technology can provide a clear 3D image of the unborn child for parents prepared to stump up the fee. It is available at a handful of clinics and ultrasound studios in England, and is on the way in Scotland.

Long before scans were available, many weird and wonderful myths sprang up to determine the sex of an unborn child.

Sam or Samantha?

For not only are prospective mums and dads intrigued by this game of 50:50 chance. So, too, are loved ones and colleagues - strangers even.

A health and safety expert who comes to assess my work station pronounces my bump to be of the masculine variety, simply by rubbing my belly.

A bump to the front means a boy

"You carry your baby out to the front - you will have a little boy," she decrees. According to this old wives' tale, if I instead had a wide bump, and so looked pregnant from behind, it'll be a girl.

Curiosity piqued, my workmates have put my bump through a battery of tests drawn from the homespun wisdom of the ages. First up was the key test. If a pregnant woman picks up a house key by the round end, it's a girl. If she grasps the long end, it's a boy. I grabbed the middle... indicating twins.

Another myth goes by the mother's age and the year of conception. In my case, both are odd numbers which means it's a girl. Ditto had both been even. But if one is odd and the other even, a boy is on the way.

And I'd felt constantly queasy in the early months - morning sickness early on means a girl, apparently.

Food glorious food

"Do you crave sweets, or cheese and meat?" asks Duncan, the workmate charged with leading the experiment. I'm a vegetarian. I do crave feta (indicating a boy) but that's more to do with the need for pregnant women to eat pasteurised cheeses, and feta doesn't always go through this process. But I do fancy a slice of cake, which means a girl.

Hi-tech scans capture more detail

There's reddish highlights in my hair: it's a boy. My feet are no colder than usual: it's a girl. Am I moody? Not at all. It swings back to boy again. Looking a little rough around the edges? No more so than usual. Boy, as a girl is said to steal her mother's looks.

I never wear gold, so we can't swing a gold pendant (one which the mother wears frequently) above my palm to see if it moves in circles - for a girl - or back and forth.

Nor is the next test any more conclusive. If the left breast is bigger than the right during pregnancy, it's a girl. If the right is bigger, it'll be a boy.

"I can't ask you that!" exclaims Duncan. And I have a policy of not discussing chests at work, mine or anyone else's.