Every Gender Selection Method based on how to X and Y chromosomes interact together. The main idea is to help Y chromosomes to implant in Egg of female for getting Boys and help X chromosomes for Girls. In this context various techniques, diet, sexual positions and timing of intercourse is proposed. Here is a brief description of each step.
PGD
Pre-implantation genetic diagnosis (PGD) using in vitro fertilisation (or IVF) is the most reliable way of influencing the sex of your baby.
During any IVF, eggs are removed from the mother and introduced, in the laboratory, to the sperm from the father.
If the couple want their child to be a particular gender, a cell is taken from each embryo three days after fertilisation, and the DNA and chromosomes are analysed. Only the embryos of the desired sex are subsequently planted back in the mother's womb.
It is, however, illegal in the UK to choose the gender of a child for social reasons, so PGD can only be carried out for medical reasons – for instance to avoid passing on genetic illnesses such as haemophilia (the disease where blood can't clot), which only affect boys.
Does it work? The only 100 per cent guaranteed way of choosing the sex of your baby
Diet
According to the study published yesterday, mothers who eat breakfast every day, preferably a bowl of cereal, are more likely to have a boy.
The headline-grabbing finding came about because, according to the research, women whose calorie intake is high at the time of conception (about 2,250 calories) have a 56 per cent chance of having a boy. Those whose intake is lower (around 1,750 calories) only have a 45 per cent chance of having a boy.
Elsewhere, there are many other theories about diet and its influence on gender, although many don't seem to be based on any hard science. For instance, to produce a boy, prospective mothers have been variously advised to eat lots of red meat (the redder the better), and salty snacks such as pretzels and crisps. Fathers should, allegedly, drink cola.
For a girl, both parents should eat a lot of fish and vegetables and gorge on chocolate, sweets and dairy products. (More colourful theories about the way diet supposedly affects gender can be found in the old wives' tales section below).
Does it work? A tiny effect at best, increasing the chances by a few per cent
Timing of intercourse
The idea that when you actually conceive can affect your baby's gender was first proposed seriously by the American doctor Landrum B Shettles, who wrote the bestselling book How to Choose the Sex of Your Baby.
The theory works, again, on the basis that male sperm swim faster than females. One of his theories was that if intercourse occurred very near to ovulation, you would get a boy – as the male sperm would beat the female in a short race to the egg.
Another theory based on the timing of intercourse was developed by another American, Dr Elizabeth Whelan.
She said that women would get a boy if intercourse was between four or six days before ovulation, when their basal temperature (the temperature one is when one wakes up) increases as part of the menstrual cycle.
If they wanted a girl they should aim to have intercourse two to three days before they ovulate. (Other theories about timing and gender can be found in the old wives' tales section).
Does it work? Nothing kills passion faster than trying to have sex to order, which would result in no baby
Sexual position
The effect of sexual position on baby gender is unproven, but most speculation about it is based around the theory that "male" sperm are small and fragile but quick, whereas "female" sperm are larger and tougher but slow.
The ancient Greeks believed that if a man had sex while lying on his right side, he was more likely to have a son.
Another long-standing theory has it that the "missionary" position is most likely to produce girl because the sperm ends up away from the cervix. This means that the sperm will have to fight through more acidic secretions to get to the womb – and as female sperm are tougher, they are more likely to get through than the males.
Having sex standing up, though, is said to produce boys, thanks to the theory that male sperm will be better at swimming, and so more likely than females to be able to swim against gravity.
Does it work? Unlikely, but it should be fun trying, nevertheless
Sperm sorting
Another scientific way of producing Janet and not John is artificial insemination after "sperm sorting" – literally separating "male" from "female" sperm.
There are two ways of doing this. The Ericsson technique works on the principle that Y-chromosome sperm (producing boys) swim faster than X-chromosome ones. The father's sperm is put through a sorting process, based on the speed it swims, and then only one particular kind is used for insemination.
The second method, microsorting, is based on the fact that X-chromosome sperm are slightly larger than the Y, carrying 2.8 per cent more DNA. Dye is added to the sperm sample, with the idea being that the larger sperm will identify themselves by soaking up more dye.
Does it work? It is better than nature but not guaranteed – it gives a nine-in-10 chance of producing a girl and a three-in-four chance of producing a boy
Old wives' tales
*In France in the 18th century it was thought that each testicle contained gender-specific sperm: so girls came from the left and boys came from the right. Men who wanted a boy were encouraged to tie off their left testicle during intercourse – or even to remove it.
*Girls are more likely to be conceived in the afternoon and on an even day of the month, while boys are more likely at night and on odd days.
*Female orgasms during sex are more likely to produce a boy, as the body produces alkaline chemicals after an orgasm, which are less likely to finish off the less hardy male sperm, which can then go on to beat the female sperm in the race to the egg.
*Men who drink coffee before they have sex are more likely to have a son, as the coffee perks up the male sperm but not the female.
*As mothers get older, they are more likely to have a boy.
*If you want a girl, sleep with a wooden spoon under your bed and a pink ribbon under your pillow.
*For a boy, only eat the ends of loaves of bread; for a girl, eat only the middles.
Do they work? If you believe these then you should watch out for the men in white coats
And... how to tell what the child's gender is when you are already "carrying"
You're said to be having a boy if...
* You're carrying the baby "low"
* You suspend a gold ring from a string over your pregnant belly and the string swings back and forth (rather than in a circle)
* The hair on your legs grows faster - supposedly due to increased testosterone in the body
* You're craving salty food
* You didn't suffer from morning sickness
* You have dry skin during pregnancy
You're said to be carrying a girl if...
* You're carrying the baby "high"
* You had morning sickness
* You're craving sweet things, such as sweets and fruit juice
* You combine your age at the time of conception with the number of the month you conceived and the resulting number is odd
* In the gold ring test, the string swings in a circle
* Your skin becomes very soft
(Of course, the best way to tell the sex of your baby is by ultrasound. And here's a tip: if you are asked: "Do you want to know the sex?", by medical staff, then you're not getting a girl. That's because ultrasound only provides certainty of the gender if the baby is male).
