Myth or reality?
Will female orgasm give you a boy?
Several techniques have claimed to help couples choose the gender of their child. The one that’s received the most attention is the Shettles Method, named after an American biologist called Landrum B Shettles, who is also considered one
of the pioneers of IVF.
Shettles believed that X and Y chromosome sperm were different in two important ways: Y sperm were smaller and more fragile than X sperm, and Y sperm were faster swimmers than X sperm. Based on these differences – yet to be proven – Shettles suggested ways parents could influence the sex of their baby, including when to have intercourse, different sexual positions and female orgasm, to increase a couple’s chances of having a boy.
However, studies have so far found little to support X and Y sperm being different in size or speed, and the only rigorous study of the Shettles method found no evidence that the timing of sexual intercourse can predict the gender of your baby.
VERDICT There are no home methods that can influence the gender of your baby.
Myth or reality?
Do mobile phones, undies and bicycles reduce sperm health?
The argument that radio waves from mobile phones can affect sperm is gaining some traction. Seeing as most men keep their phones in their front pockets, they are pressed up against the sensitive sperm factory of testes. Wearing tight-fitting undies may not just be uncomfortable, it can increase the temperature of the scrotum, affecting performance. And sitting in a saddle of a bike similarly raises the temperature of the testes and can also lead to physical trauma.
VERDICT There is accumulating evidence that mobile phones, tight underwear and bike riding reduce sperm health.
Myth or reality?
Do women gain a child and lose a tooth?
The basic premise of this old saying is that, along with backache, reflux and stretch marks, tooth loss is a natural consequence of pregnancy. A number of studies have found that tooth loss is more common among women with a large number of children, so this old wives’ tale may be true.
However, the better known theory – the growing baby drains calcium from her mother’s teeth – is false. If the mother’s calcium intake is insufficient during pregnancy, the extra calcium required for her baby’s skeletal development will come from the mother’s bones, not her teeth.
Studies show that pregnancy hormones lead to changes in the tissue surrounding and supporting a mum-to-be’s teeth. This can cause gums to swell and make teeth more susceptible to gingivitis.
VERDICT Women who’ve had multiple pregnancies really are more likely to lose their teeth. The most likely scenario is that the higher-than-normal levels of hormones in pregnancy change the oral environment and increases a woman’s susceptibility to dental disease and subsequent tooth loss.
Myth or reality?
Will your baby love carrots as much as you do?
One belief shared by numerous cultures around the world is that the food a woman consumes during her pregnancy has long-lasting effects on her children.
One American study found that babies of mothers who drank carrot juice during the last stages of their pregnancy were later shown to have a preference for an infant cereal mixed with carrot juice, compared to babies whose mothers drank water in the final three weeks of their pregnancy.
In another study, the offspring of rat mothers fed a high-fat diet of junk food during pregnancy were also more likely to have a preference for these foods
after birth, particularly peanut butter and hazelnut spread.
VERDICT What a mother eats when she is pregnant can influence the food preferences of her offspring. Well-designed studies show how a mother’s diet can change the smell of the amniotic fluid and, when your bub swallows this, the smell receptors in her nose become familiar with the flavours. Later on, once she is born, she will have a preference for foods with these flavours.
Myth or reality?
Does sugar turn your angel into a little devil?
Parents swear their children go ‘hyper’ after a hit of sugar and, if you’ve been to a few children’s parties, it is difficult to argue against the existence of a sugar rush. Sugary snacks, the hypothesis goes, raise the level of sugar in the blood, which provides our brain and body with more fuel than we typically need, and thus we are just gagging to expend this energy.
The problem, however, is that these beliefs are not consistent with what we know about how the body works and how it processes sugar. The weight of scientific evidence indicates that sugar does not cause hyperactivity in children. Instead, our observations of children going bonkers after eating a fistful of jelly beans appears to be due to our own expectations of this outcome. Excess consumption of foods full of simple sugars tends to occur at birthday parties and other fun events, which are jam-packed with games, friends and a truck-load of other enjoyable activities specifically designed to excite children. Sugar, in the end, may just be an innocent bystander to the electrifying energy that accompanies these events.
VERDICT Sugar does not cause hyperactivity in children.
Myth or reality?
Will Mozart make my baby smart?
The origin of this popular claim is a 1993 California study which found students performed better in an IQ test after listening to Mozart, compared to sitting in silence or listening to a relaxation tape. However, many studies later and the answer lies not with Mozart, but with the power of certain forms of music to grab our attention and influence mood. Increased levels of attention and arousal will lead us to perform better when we undertake certain tasks. There was nothing special about Mozart, and there was no increase in actual intelligence. Rather, the engaging music had made people more attentive to the demands of the IQ test.
VERDICT Listening to Mozart will not make your baby smarter
This is an edited extract from Will Mozart Make My Baby Smart? ($27.99) by Professor Andrew Whitehouse of the Telethon Institute for Child Health Research.
