If you're pregnant and want to know whether your baby is a boy or a girl, or planning a pregnancy and have a strong preference for whether you conceive a baby boy or a baby girl, some believe the Chinese Conception Calendar should be your first port of call.
Also called the Chinese Pregnancy Calendar, the chart was discovered hundreds of years ago and still exists at Beijing's Institute of Science. It was originally used by Chinese royalty to help swell the ranks of male babies, thus ensuring the continuation of the royal line.
Based on the Chinese Lunar calendar, the chart uses a combination of the mother's age at the time of conception and the month in which the baby is conceived to 'predict' whether the baby will be a boy or a girl.
Of course, you can just wait and ask about your baby's sex during your ultra-sound scan at 20 weeks - but even scans have been known to get it wrong. I'll never forgot the mum from my antenatal class who, after waiting seven long years to conceive, celebrated the news that she was expecting a boy by painting the walls of his nursery with cute macho cars and robots, and buying every conceivable bit of baby clothing and paraphernalia in various uncompromising shades of blue. Several months after the arrival of her beautiful baby girl she was still apologising for the fact that her daughter was dressed head to toe in blue, on account of the fact that scans aren't infallible.
And while a test that can identify your baby's gender before 20 weeks does exist, it doesn't seem likely that it will be routinely available in the UK any time soon. So if you're pregnant and want to know whether you're having a girl or a boy the Chinese conception chart can be a fun way to find out.
How to use the Chinese Pregnancy Calendar
To use the Chinese Pregnancy Calendar you simply find your age at the time of conception, then trace along the corresponding line on the chart until you reach the month in which you conceived. If the corresponding square is pink it means - surprise surprise - that you're carrying a girl, while a blue square means your baby will be a boy.
Lisa Durbin is a mother of one son, Jack, and two daughters, Mia and Isla. She consulted the Chinese Pregnancy Calendar during each of her pregnancies. "Only the gender of one of my three kids was correctly predicted by the calendar," she says. "But calendars that take your lunar age into consideration are supposedly more accurate than the ones that just use your regular age. So for me, the calendar would have been wrong for all three kids - but the calendar that used my lunar age got the sex of one baby right."
Mum of four Jude Burrows can't see the point of the calendar. "Surely it's just easier to ask your midwife?" she says, bemused. Mother of two Catherine Cooper agrees. "Honestly. How can something like that possibly work?"
Lisa points out that the calendar is just a bit of fun, particularly for mums who decide not to find out their baby's sex but can't help playing the guessing game. "I certainly didn't take any of those gender 'tests' seriously," she says. "We found out the sex at the 20 week scan for our first two, and left it as a surprise until the birth with number 3."
Cathryn Scott, mum of Eva, nearly one, agrees. Cathryn decided not to find out the sex of her baby as she was keen to experience the element of surprise at the birth. "I was just so happy to be pregnant after a previous miscarriage, it didn't matter to us whether it was a boy or a girl," she says. "However, like a lot of mums-to-be, I was still intrigued by all the old wives' tales. I answered a couple of online quizzes about whether I was craving orange juice, the shape of my bump, the sound of the baby's heart beat (like a train or galloping horses) etc and each predicted which sex you were likely to be carrying. Different quizzes gave me different answers and this was just one more. I certainly didn't take it seriously and I wouldn't have been upset it if it had been wrong."
The Chinese Conception Calendar predicted that Cathryn's baby would be a girl - and she was! Eva is nearly a year old and surprised most of Cathryn's friends and family and even the midwives who were all convinced she was going to be a boy.
However, Cathryn knows of one mum who had a baby boy after the Chinese Conception Calendar predicted she was having a girl. "She never said she was disappointed by the test or by having a boy but I think deep down she really wanted a girl.
"If you want to know the sex, I don't see why you would rely on something like this when you could opt to find out at your scan instead. That said, I don't even trust the professional antenatal scans that can predict the sex. I've never bought a gender-specific present until after the baby was born, just in case, as we've all heard those tales of scans predicting the 'wrong' gender."
You can bet your bottom dollar that the Swedish couple who refuse to disclose the gender of their two year old child to anyone in order to avoid steretyping probably didn't bother consulting any gender prediction tests. The child's mother said "It's cruel to bring a child into the world with a blue or pink stamp on their forehead."
Ironically, what really determines the gender of your baby is neither the age of the mother or the month in which she conceives - but the baby's father. Or specifically, his sperm. Chromosomes carry hundreds of genes which determine everything from the baby's hair and eye colour to its blood group and gender. A fertilised egg contains one sex chromosome from the mother's egg - always the X chromosome - and one sex chromosome from the father's sperm, which may be either an X or a Y chromosome. An egg fertilised by a sperm containing an X chromosome will be a baby girl, while an egg fertilised by a sperm containing a Y chromosome, will be a boy.
So short of genetic testing on the potential father of your unborn child, it's probably best not to paint the nursery or go mad in Mothercare on the basis of any gender prediction charts or quizzes.