Some experts claim you CAN choose the sex of your baby by timing when you conceive – but are they right?
Trying for a girl? Tuck a wooden spoon or pink baby clothes under the bed—or even pop a coin in your mouth during sex.
At least, that’s what old wives’ tales have long suggested could help parents sway the sex of their baby.
Now a social media trend is reviving the idea, this time claiming to have science behind it. Under the hashtag #GenderSwaying, the fad has drawn tens of millions of views as mothers detail elaborate efforts to get the son or daughter they longed for.
In one clip, seen by more than 115,000 people, influencer Alexis Bremner admitted: ‘I really really really wanted a baby girl for our first baby. So before trying to conceive, I did copious amounts of research.’
Bremner decided to follow the Shettles Method, a theory developed in the 1960s by American gynaecologist Dr Landrum Brewer Shettles.
He argued that timing sex with ovulation could influence a child’s sex, claiming that Y-chromosome ‘male’ sperm swim faster, while X-chromosome ‘female’ sperm are slower but survive longer.
According to the method, couples hoping for a girl should have sex a couple of days before ovulation. Those wanting a boy should wait until the day of ovulation itself.
The idea has inspired spin-offs such as the Babydust Method, created by US microbiologist Dr Kathryn Taylor, which has a Facebook forum of more than 55,000 followers. Dr Taylor claims an 87 per cent success rate—though there have been no clinical trials to prove it.
In one clip, seen by more than 115,000 viewers, self-professed ‘girl mom’ Alexis Bremner (pictured) told of her tactics to sway the gender of her first child.
Mum-of-three Nicole Shamlin also tried to gender sway, telling her nearly 50,000 viewers of how she and her partner ensured they ‘finally got their baby girl’
After two sons, TikToker Carlie Roman was desperate for a baby girl. So she and her OBGYN husband used the Shettles method to conceive – and were successful
Even fertility apps are buying in. The Fertility & Period Tracker app uses Shettles’ logic to suggest the ‘best days’ for conceiving a boy or girl, and boasts thousands of reviews from mothers who say it worked for them.
Mum-of-three Nicole Shamlin told her nearly 50,000 TikTok followers she finally conceived a daughter after following the advice: ‘I believe the cycle that we got pregnant, we did it two days before ovulation.’
She also altered her diet, taking cranberry, magnesium and calcium supplements during her fertile week in the belief it would give ‘boy spermies’ less chance of survival.
This reflects a 2010 Dutch study suggesting a calcium-rich, low-sodium diet increased the odds of conceiving a girl. Other forums advise women to eat acidic foods for a girl, or alkaline foods for a boy, to change vaginal pH.
Yet fertility experts say none of these approaches work.
Dr Bassel Wattar, endocrine gynaecologist and associate professor of reproductive medicine at Anglia Ruskin University, said: ‘The Shettles method is not new—it’s been around since the 1960s. But there’s no evidence behind it.
‘Studies show it has no statistical effect on a baby’s sex. The only thing that decides that is which sperm fertilises the egg—whether it has an X chromosome or a Y chromosome.’
He explained that although X and Y sperm may appear to move differently under a microscope, in practice it makes no difference: ‘Fertilisation happens in a split second. Swimming pattern doesn’t matter, as long as there’s enough sperm reaching the egg.’
As for diet, he is equally blunt: ‘The pH in the vagina changing does not actually affect sperm. If you have an overly acidic vaginal pH it can weaken or kill sperm, but that just makes it harder to get pregnant—not more likely to conceive one sex over the other.’
In countries where gender selection is legal—including parts of the US, Mexico, Thailand and Cyprus—IVF clinics can biopsy embryos to reveal their sex.
A newer technique known as microsorting can even separate X and Y sperm before fertilisation, though it is available only in a handful of centres.
‘In short, there’s not much you can do to sway the sex unless you’re willing to pay for IVF abroad,’ Dr Wattar said.
‘Couples who still want to try these methods should know that restricting intercourse during the fertile window can actually delay conception.
‘We advise couples to have unprotected sex at least three times a week to maximise their chances.’
That hasn’t stopped women on TikTok from crediting Shettles with their ‘success’. Jasmine Jackson told her followers she conceived a girl after a boy by following the method.
Carlie Roman, who has more than 135,000 followers, said she and her OBGYN husband used it to conceive their daughter after two sons: ‘This worked for us—obviously it’s not necessarily scientifically backed so it won’t work for everyone.
Jasmine Jackson told her TikTok followers that she successfully used the Shettles Method to conceive a baby girl, after having a son
Dr Natalie Crawford advised couples who are suffering from infertility not to try the Shettles Method
‘We had time on our side so we had time to give it a shot.’
The desire to influence a child’s sex is not new. A 2017 survey found nearly a quarter of UK mothers admitted to being ‘very disappointed’ if their child wasn’t the sex they’d hoped for.
Women were twice as likely to prefer daughters, while fathers were three times more likely to want a boy.
For some, gender swaying may feel like harmless fun. For others, it offers false hope. As Dr Wattar puts it: ‘The movement of sperm in the female reproductive system is quite independent of any other factors—no food, diet or medication can sway it.’
