Can You Really Choose The Sex Of Your Baby?

It's a strange comment that expectant couples sometimes get: "Are you hoping for a boy or a girl?" Because whatever it is you might be hoping for, deep-down, it's not like you actually have a say in the matter, right? Unless you're undergoing in-vitro fertilization specifically to avoid a sex-linked genetic disorder, you've got close to a 50/50 shot of getting a boy or a girl (per Parents). Except, some parents insist that they were able to influence the outcome of their pregnancies by going through some interesting rituals; a steady diet of yogurt and sweets, according to some, summons a daughter, while others say standing-up sex results in a son (per What to Expect). 

So is there any truth to the concept that you can "try for a girl" or "try for a boy," without spending thousands of dollars on IVF? A doctor named Landrum B. Shettles insists that there is, and his bestselling book, How to Choose the Sex of Your Baby, claims to have a 75 percent success rate. Initially introduced in the 1960s, what's now called "The Shettles Method" purports that the timing of intercourse and ovulation can influence whether male or female sperm "win" that race to fertilize the egg.

It's the dad-to-be's sperm that determines the baby's sex, and Dr. Shettles observed that boy-producing sperm (with a Y chromosome) had different characteristics than girl-producing sperm (with an X chromosome). The Y sperm appeared faster and lighter, and the X sperm were heavier, and while they swam more slowly than the boy sperm, they lived longer (per Healthline). Considering that the egg only makes her long-awaited appearance every 28 days or so for less than a day, timing of intercourse is everything, per Shettles. Sex that occurs during ovulation gives the Y sperm a better shot at finding that egg first, while earlier-in-the-cycle intercourse gives those X sperm a better shot.

But was Dr. Shettles right about his sex timing theory? Many experts claim it's just a myth. "Guess what? It doesn't work. There's never been one shred of evidence that it works," Dr. Richard J. Paulson, chief of Reproductive Endocrinology and Infertility at the Keck School of Medicine at the University of Southern California, told ABC News. "I'm not even sure what research this was based on, but because he was a doctor, people believed it," he added. Plus, following Dr. Shettles' advice to the letter — such as using a vinegar douche to sway the odds of conceiving a girl — may actually decrease your odds of getting pregnant, noted VeryWellFamily.