Many parents are curious whether there is anything they can do to influence their baby’s sex before conception. While no natural method can guarantee a boy or a girl, several popular gender-swaying theories claim to improve the odds.

These approaches typically focus on factors such as timing intercourse, dietary changes, supplements, body pH, and lifestyle habits. Some have limited research behind them, while others are based largely on anecdotal reports and old wives’ tales.

If you’re curious about these theories, here’s a look at some of the most commonly discussed methods for conceiving a boy or a girl.

Can You Influence Baby Gender?

Scientists have studied whether factors such as diet, timing, and reproductive tract conditions may influence the likelihood of conceiving a boy or girl. While some studies suggest possible associations, no natural method has been proven to reliably determine a baby’s sex.¹ Still, many of these theories remain popular among parents hoping to sway the odds one way or the other.

How To Improve Your Chances of Conceiving a Girl

The following theories are commonly discussed among people hoping to conceive a girl. While none are guaranteed, they are among the most widely known gender-swaying approaches.

1. Timing Is Everything

According to The Shettles Method, developed by Dr. Landrum Shettles in the 1960s, X-chromosome (female) sperm swim more slowly than Y-chromosome (male) sperm and live longer than male sperm.¹ Because of this, you don’t want to wait until you’re ovulating if you want to conceive a girl. You would aim to have intercourse two or more days before ovulation so that the male sperm will die off before reaching the egg.

Related: How To Conceive a Girl: Popular Gender Swaying Theories

2. Chinese Lunar Calendar

This is an ancient tool many people use when trying to predict or influence baby gender, though its accuracy has not been scientifically validated. According to this theory, some people try to conceive during the months that the calendar predicts a girl. To make it easier on yourself, visit our Chinese Gender Predictor and Calendar!

3. Female Orgasm Theory

One gender-swaying theory suggests that female orgasm may create conditions that favor faster-moving Y-chromosome sperm. Because of this, some people believe avoiding orgasm may improve the chances of conceiving a girl. However, there is little scientific evidence supporting this theory.⁹

4. Frequency of Intercourse

Another theory suggests that more frequent intercourse may lower sperm concentration, potentially favoring X-chromosome sperm. Some versions of this theory also recommend shallower penetration and gentler sexual activity when trying to conceive a girl. However, evidence supporting these recommendations is limited.⁸

Related: Signs You’re Having a Girl: 23 Fun Clues to Look For

5. Diet Changes

Eating certain foods can potentially improve your chances of having a girl.⁵ Salt is supposedly not good for trying to conceive a girl, so some gender-swaying theories recommend limiting it.⁶ Here are some of the foods commonly discussed in girl-conception diet approaches:

Foods Often Recommended

• Milk and other dairy products, such as cheese and yogurt7
• Unsalted foods
• Certain vegetables
• Rice and pasta
• Mineral water
• Limited amounts of meat
• Potatoes

Foods Often Limited

• Wine and beer
• Salt and salty foods
• Spinach
• Tomatoes
• Mushrooms
• Fresh fruit
• Chocolate
• Coffee
• Tea

6. Tight-Fitting Underwear Theory

Have your partner wear boxer briefs or tighty whities and tight pants to keep his genitals closer to his body. The temperature of the testes is the issue. Since the testes must be cooler than core body temperature, the closer they are to the body, the warmer they get, and the lower the sperm count will be.⁸ This may increase your chances of conceiving a girl.

7. Other Girl-Conception Myths

Other gender-swaying theories suggest that factors such as the time of day or the day of the month may influence the chances of conceiving a girl. These claims are considered old wives’ tales and are not supported by scientific evidence.

How To Improve Your Chances of Conceiving a Boy

These theories are often suggested for people hoping to conceive a boy. As with all gender-swaying methods, the evidence is limited and results are far from guaranteed.

1. Track Your Ovulation

Since male sperm travel faster and don’t live as long as female sperm, have sex on the day of ovulation.¹

2. Less Sex

You want your partner to have a high sperm count, so if you have sex frequently, this is dropping that number. This theory is based on the belief that Y-chromosome sperm may be more fragile than X-chromosome sperm. The higher the sperm count, the greater the chance a male sperm reaches the egg first. So, avoid sex for a week before ovulation, and only have sex once on ovulation day to keep the sperm count high. Some versions of this theory also recommend avoiding activities that raise testicular temperature, such as frequent sauna or hot tub use.⁸

3. Female Orgasm Theory

Some gender-swaying theories suggest that female orgasm creates a more alkaline environment in the reproductive tract, which may favor Y-chromosome sperm. Because of this, some people believe orgasm before ejaculation may improve the chances of conceiving a boy. However, scientific evidence supporting this theory is limited.⁹

4. Acidic-Free Diet

As said earlier, acidic conditions supposedly kill male sperm. You might want to try an alkaline diet a few weeks before conception.¹⁰ Also, increasing your sodium and potassium intake is suggested for those trying to conceive boys.^10,11

Foods Often Recommended

• Salty foods
• Meat
• Fish
• White flour
• Pasta
• Fresh fruit

Related: 8 Foods That May Help You Conceive a Boy

5. Weight and Activity Theories

Some gender-swaying theories suggest that maintaining body weight and avoiding significant weight loss may favor conceiving a boy. While this idea is sometimes discussed in gender-selection communities, evidence supporting it is limited.

6. Deep Penetration Theory

One theory suggests that deeper penetration may deposit sperm closer to the cervix, potentially giving faster-moving Y-chromosome sperm an advantage. Positions associated with deeper penetration are often discussed in boy-conception theories, although evidence supporting this idea remains limited.⁹

7. Caffeine

Some gender-swaying theories suggest that caffeine may temporarily increase sperm activity.¹² Have your partner drink a caffeinated beverage before intercourse.

Related: Signs You’re Having a Boy: 23 Fun Clues to Look For

8. Boxers, Not Briefs

Your partner needs to keep his genitals cool by wearing boxer shorts and loose-fitting trousers to keep the testis’ temperature lower to improve the quantity and quality of sperm.^8,13

9. No Smoking or Drinking

If your partner drinks and smokes, it’s time to stop. Men who smoke and drink heavily are more likely to have a low sperm count, lowering your chances of conception, especially with a boy. Additionally, marijuana has been shown to have a similar effect as cigarettes regarding sperm count.² Although a recent study shows that marijuana may increase sperm count in males.^3,4 Cocaine and other hard drugs are also known to lower sperm production.¹⁴

10. Other Boy-Conception Myths

Other gender-swaying theories suggest that factors such as the time of day or the day of the month may influence the chances of conceiving a boy. These claims are generally considered old wives’ tales and are not supported by scientific evidence.

Final Thoughts

While many parents enjoy exploring gender-swaying theories, no natural method can guarantee a boy or a girl. If you decide to try any of these approaches, it’s best to view them as interesting possibilities rather than proven outcomes. Ultimately, the goal is a healthy pregnancy and baby, regardless of sex.