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Battle of the Sexes

Everything You Need To Know About Choosing The Sex Of Your Kid

Your child’s sex is pretty much up to you. Well, not you, personally. Rather it’s up to your swimmers, some of which carry an x chromosome, and some of which carry a y. Why? Because when they meet with the x-carrying egg, your kid’s parts are determined. An xy pair results in a boy. An xx pair results in a girl. And an XXX results in a Vin Diesel, which is obviously super rare (thank goodness).

Of course some couples really really REALLY want to have a boy or a girl, specifically. If you count yourself among that number, there are some old wives tales suggesting activities to tilt the odds. But there’s really only one way to practically guarantee your choice.

The Science

The conventional wisdom is that the boy/girl ratio is around 50:50. The odds, then, are even. That’s because there is a pretty even distribution of x and y sperm being produced in your pants factory.

Most natural sex selection techniques are built on boosting the chances of one type of sperm reaching the egg before the other. That’s nice considering some Roman techniques suggested things like removing ovaries and testicles or tying up one ball. So, thank goodness for progress.

Fact Vs. Fiction

Happily, people aren’t removing ovaries and testicles willy-nilly in order to have a boy or a girl. However, that doesn’t mean current natural techniques aren’t seated in misconceptions. The main one being: x chromosome-carrying sperm are big, slow and rugged; while y chromosome-carrying sperm are fast and short lived.

To date, the balance of scientific research suggests no recognizable difference in size, speed, or life expectancy between x and y sperm. So you can rest assured most methods built on that hypothesis will be as effective as chanting the word “boy” repeatedly as you climax (which is ill-advised for many reasons).

That said, researchers have found a very slight difference in the mass of the different sperm. This makes sense considering the x and y chromosomes contain different amounts of chromosomal material. There’s that extra leg in the x, after all.

The Natural Methods

With the science in mind, here are the most popular natural methods of sex selection. You can give them a shot. But know they’re not going to really do much for you, aside from giving you something else to do while you’re trying to make a kid.

The Boy Or Girl Diet

The idea here is that your partner changes her diet to add calories or certain minerals and vitamins that will change her body chemistry and make it more hospitable to male or female sperm. While one study suggests it will change the odds of getting what you want to 56/44 in your favor, it’s probably not the best idea to mess with your diet prior to pregnancy. Always talk to a doctor before doing something like this.

The Timing Method

The hypothesis of the timing method is based on slow x versus fast y sperm. The thought is that the farther away you have sex from ovulation the more likely your chances of conceiving a girl. Sadly the research just doesn’t back this up. And figuring out when your partner is ovulating can be frustrating and complicated.

Sexual Positions

This is also based on the slow and fast sperm hypothesis. The thought is that the closer you can get the sperm to their target, the better the chances are for those fast y sperm to get there first. But the movement of sperm is hugely complicated and relies on way more than their tails. That doesn’t mean you shouldn’t change up the fun. Do what makes you feel good.

The Scientific Methods

There are some science-based methods for sex selection. But there is a huge caveat: many are unavailable in the U.S., either because they have not been proven or are considered unethical. Nevertheless, they are proven to increase the chances of conceiving either a boy or a girl.

The Ericsson Method

There are a handful of clinics in the U.S. that use this method for sex selection which is said to increase chances of getting your choice of boy or girl by around 70 percent. This method is based on the infinitesimally small mass difference between x and y sperm due to the chromosomal material.

In this method, sperm are made to swim through an oozy substrate. X sperm supposedly sink and slow in the substrate while y sperm cruise along. They are separated accordingly. Is the cost worth a 30 percent chance of failure? That’s up to you.

Sperm Sorting

This method was first pioneered with livestock and results in about a 90 percent chance of sex selection. It involves staining sperm chromosomal material with a substance that glows in fluorescent light. A greater glow indicates more material, which in turn indicates a female sperm.

There were human trials for this method, but they didn’t really get anywhere. Currently, it is not allowed in the United States due to FDA rules concerning possible side effects linked to the process.

IVF and PGA

This is the only method to virtually guarantee the sex of your child. It is only available to couples undergoing in vitro fertilization if the doctor deems it ethical. The method, called preimplantation genetic diagnosis, tests the chromosomal makeup of a fertilized blastocyst before implanting it in the uterus. It remains largely controversial.

The bottom line, of course, is that while it might be nice to select a boy or a girl, you’re probably going to be delighted no matter who you happen to meet after that long 9 months. Unless it happens to be a Vin Diesel, in which case you’ll probably be furious, fast.