The Shettles Method of gender selection

Boy or girl ... What does science say on whether timing sex can result in shifting the gender ratio?
Boy or girl ... What does science say on whether timing sex can result in shifting the gender ratio? 

Gender selection is a much-talked of topic among our forum users, especially those pregnant or trying to conceive. While many consider gender selection something of an urban myth, others swear by it. Either way you have a 50 per cent chance of 'getting it right'!

We've included some information below on gender selection, but bear in mind that it doesn't have a very high success rate, and using some of these timing methods may decrease your chances in conceiving. If falling pregnant is your number on priority, irrespective of gender, you might be better off focussing on timing!

Gender selection methods are often referred to as the Shettles Method, as it was invented by Dr Shettles. The theory is that men produce two types of sperm which already contain the sex chromosome, pre-determining the sex of the baby-to-be; the X chromosome makes a female, and Y chromosome makes a male. Shettles found from his studies that the male sperm are smaller, weaker and faster than the female sperm, which are bigger, stronger and slower, and recommends the following suggestions to couples trying to choose the sex of their baby.

You're more likely to have a boy if…

  • You have sex on the day of ovulation, as male sperm swim faster and will reach the egg first.
  • If you have sex during times of peak fertile mucus (or no more than 12 hours before ovulation). To detect ovulation you can chart your cycle or use an ovulation prediction kit (OPK). If your chart shows a temperature dip, or your mucus changes from peak to thick, this can also be a good time to have sex.
  • When the vaginal environment becomes alkaline - which is on the day of ovulation - as an acidic environment can kill male sperm at other times.
  • Do not have sex 4-5 days prior to ovulation.
  • Sexual position is said to influence gender selection due to depth of penetration and pH levels. The closer to the opening of the vagina, the more acidic the woman's reproductive tract is. Deeper penetration (e.g. doggy-style) is more ideal for a boy, as the male sperm are closer towards the egg, giving them a head start on the female sperm (as well as being further away from the more acidic areas).
  • For a boy, the woman should try to achieve orgasm either before or at the same time as her partner - or if you are lucky enough, multiple female orgasms can help! The theory on this is that the waves of the orgasm help to draw up the sperm quicker to the egg, again the boys getting a head start on the girls.

You're more likely to have a girl if…

  • You have intercourse two to four days prior to ovulation. The female sperm can survive longer so if you sex outside peak fertile mucus times, the chance of having a girl may be increased. Please note however if you follow this method your chance of conceiving at all may be reduced.
  • An acidic pH level kills weaker sperm (male sperm), have sex during this time - outside the day of ovulation as your vaginal pH levels are most alkaline during this time.
  • You have sex daily from the end of your period until 2-4 days prior to ovulation, then no intercourse 2-3 days after ovulation.
  • Have sex in the missionary position - according to Shettles!
  • Avoid orgasm - for the woman!

To try for a boy, Dr Shettles suggests men try and keep the scrotal temperature cool - so no hot spas or baths, tight clothing or underwear. Boxer shorts are a good alternative. He also recommends no scuba diving, heated vehicles for extended durations, or other areas of high heat. A few cups of strong coffee half an hour before intercourse favours a boy.

Success rate?
Shettles claims that his methods for a boy have a success rate of 80-85 per cent, and the methods for a girl a little less at 75-80 per cent.

Discuss gender swaying in our trying to conceive buddy groups.