The truth about conceiving a boy

Are you dreaming of having a daughter? Or would you do anything to have a boy? Well, if you’ve taken your desires to the Internet, you’ll know there’s no lack of enthusiastic advice to sway the odds of conceiving a boy or a girl. Time when you have sex! Change what you eat! Don’t orgasm! Be sure to orgasm!

Generally speaking, there’s about a 51 percent chance you’ll have a boy and 49 percent chance you’ll have a girl. But can the timing of when you have sex, how much you enjoy yourself or what you eat change these odds?

“There’s not a lot of scientific evidence that any of this works,” says naturopathic doctor Erica Nikiforuk. Her Toronto practice has a focus on fertility, and while many of her clients ask her about what they can eat or do to influence whether they will conceive a boy or a girl, she likes to redirect the conversation. “I like to encourage focusing on a healthy conception,” Nikiforuk says.

That means approaching any of the diets purported to influence gender with caution. For example, one theory suggests that sperm with an X chromosome, which would produce a girl, can survive better in times of stress. So if a woman wanted a girl she would try to mimic that by eating less protein and fewer calories overall. And while losing a bit of weight might help some women conceive in general, for others it could be detrimental to their health.

“We have to tailor your diet to what your baby needs,” says Nikiforuk. “You don’t want to go to a caloric deficit or a nutritional deficit. That’s not the way to start a healthy pregnancy.”

Another approach involves shifting the pH balance in your cervical mucus by changing your diet. For example, girls are said to prefer an acidic environment, so you would avoid salt, yeast, caffeine and many meats, but partake in milk, strawberries and garlic. But even if you could shift your pH—our bodies have a pretty strong internal control mechanism for it—there is no proof this would guarantee one sex.

So if you’re thinking of changing your diet to “sway” a gender, Nikiforuk suggests first talking to a doctor, naturopath or dietitian to find out if the changes you’re planning on making are a good idea for your body.

When it comes to timing intercourse, the theories conflict. The much-publicized Shettles method, named after in vitro pioneer Landrum B. Shettles, proposes that sperm carrying the Y chromosome (for a boy) are faster but more fragile. So if you want to conceive a boy, you should have sex close to ovulation so they’ll beat the X chromosomes to the egg, use a rear-entry position for deeper sperm deposit, and try to ensure the woman orgasms, which will help those Y-carrying sperm get there even faster.

“This has been refuted by several researchers since then,” says Alix Bacon, president of the Midwives Association of BC. “Yet my clients still ask me about it, and try it.” She adds, “No one is successful.”

Nikiforuk says she sees no harm in tracking ovulation and timing intercourse, but says parents shouldn’t get too hung up on having one gender over another. Particularly since other studies show that having sex close to ovulation might increase your changes of having a girl—the opposite of the Shettles method.

“I don’t like to raise my patients’ expectations,” she says. “What would be the emotional consequences, if a woman is timing intercourse and doing a diet, and she finds out she’s having the sex she doesn’t want to have? We just want to be supporting the new couple and new mom on their journey, and not getting caught up in the sex of baby.”

Read more: 10 old wives’ tales for predicting gender Chrissy Teigen and John Legend chose the sex of their baby The debate: Should parents find out their baby’s sex?