So you’ve decided to have a baby, and you wish you could tip the odds in favor of a certain sex. Maybe you have a house full of boys who are just desperate for a little sister to pick on. Or perhaps you want a strapping young lad to carry on the family name. No matter what the reason, getting to choose the gender of your baby sounds mighty appealing. But is it really possible to increase your odds of having one or the other? Some doctors and scientists say yes … and it’s as easy as creating the right circumstances at conception.

What determines a baby’s sex?

A baby inherits two sex chromosomes from its parents: one from its mother, who always contributes an X chromosome, and one from its father, who can contribute either an X or Y chromosome. Therefore, it is technically the male who determines the baby’s gender. If the baby ends up with two X chromosomes, it will be a girl; an XY chromosome, and there’s a boy in the making. Roughly half of the father’s sperm is “male” – or Y-bearing – sperm, and the other half is “female” X-bearing sperm.

So how can you possibly influence which sperm fertilizes the egg?

This is where the methods of gender selection come into play. There are currently two prominent theories on low-tech sex selection, proposed by Dr. Landrum Shettles and Elizabeth Whelan, Sc.D. Unfortunately, their methods contradict each other, so it confuses things a bit. Let’s take a look at each theory.

The Shettles Method

Dr. Shettles asserts that XY (boy-making) sperm are faster than XX sperm, but that they die out faster. XX sperm, the kind that makes girls, are slower than XY sperm but hardier – meaning they are more able to withstand the acidic environment of the cervix, so they can hang around longer. If you desire a boy, according to Dr. Shettles, you should:

• Time intercourse as close to the moment of ovulation as you possibly can (you can determine ovulation time by using ovulation predictor kits or charting your basal body temperature). The idea behind this is that since the XY sperm are faster, they’re more likely to reach and fertilize the egg first.

• Have intercourse in a position that allows the deepest penetration possible, such as rear entry or “doggy-style.” This is because with deep penetration, the sperm will be deposited closest to the cervix where the environment is more “XY-friendly” and the XY sperm will have less distance to travel.

• Abstain from intercourse for four to five days before ovulation, and then only do it on the day of ovulation.

• Make sure the female partner has an orgasm to increase the XY-favorable alkaline secretions in the vagina.

• Avoid heat and tight clothing in the testicular area; these things will kill off the less hardy XY sperm faster.

And to get a girl, according to Shettles, you should:

• Have intercourse two to three days before your estimated ovulation date so that the XY sperm will die out and the XX sperm, since they’re hardier, will be able to reach the egg.

• Have intercourse with shallow penetration, which gives the slower but longer-living XX sperm the advantage.

• Avoid orgasm, if you’re the female partner, to keep the vaginal environment slightly acidic and friendlier to the XX sperm.

In his earlier publications, Dr. Shettles suggested that to increase the odds of a girl, women should use a vinegar and water douche before intercourse; he has since retracted that suggestion.

The Whelan Method

Whelan’s technique for gender selection is basically the exact opposite of Shettles’ method. She purports that the biochemical changes in a woman’s body happen earlier than Shettles theorized, and that you should time intercourse 4 to 6 days before ovulation to get a boy, and 2 to 3 days before ovulation for a girl. Critics of her method say that having intercourse 4 to 6 days before ovulation is too far away from the release of the egg to even get pregnant, let alone with a boy baby.

Whelan also suggested that women follow a certain diet: if you want a boy, make sure your diet is rich in salt and potassium. If it’s a girl you’re after, your diet should include lots of calcium and magnesium. Examples of “boy diet” foods are salty meats such as bacon, ham, or sausage, salted chips and nuts, and lots of carbohydrates. Some “girl diet” foods include dairy products, ice cream, fruit juice, and very low- or no-salt items.

Other ways to determine your baby’s sex …

There are a few other techniques that you can use to determine the gender of your baby that are statistically more accurate than either method we’ve just discussed – but they’re all expensive, high-tech laboratory-type procedures that most people aren’t willing to fork over thousands of dollars (or go through the hassle) for.

The bottom line is, we can do things to try and increase the odds in our favor, but inevitably it isn’t up to us – we get what we get. And for most couples, although they may have a slight preference, a healthy baby is a blessing and a gift regardless of what gender it turns out to be.