She’s Been Running the Show All Along. What a 2020 Study Revealed About Sperm, Eggs, and Choice

By Sway natural

For decades, the story of conception has often sounded like a high-stakes sprint: millions of sperm, racing through the reproductive system like Olympic athletes, all vying to be the first to reach the egg. The fastest one wins. The prize? Fertilization.

It’s a simple, familiar story - and largely, a male-centric myth.

Thanks to a 2020 study by researchers at Stockholm University and the University of Manchester, we now know the egg isn’t a passive prize at the finish line. It’s a powerful decision-maker in its own right.

The study found that eggs release specific chemical signals - called chemoattractants - to attract preferred sperm. Even more surprising? The same egg can prefer sperm from one man over another, suggesting a built-in biological filter based on compatibility.

“Follicular fluid from one female was better at attracting sperm from one male, while fluid from another female attracted sperm from a different male…” - Dr. John Fitzpatrick, University of Stockholm, Lead author, Proceedings of the Royal Society B (2020)

In other words, it’s not just about speed - it’s about fit.

And once the egg selects a sperm, it shuts down all other contenders. Literally. It releases a chemical that causes the heads of the remaining sperm to detach - a kind of molecular lockout.

No second chances. Just the one she chooses.

🧪 What Does This Mean for Gender Swaying?

At Sway natural, we acknowledge the egg’s role in choosing which sperm succeeds - especially in the context of diet-based gender swaying.

While it’s true that each sperm carries either an X (girl) or Y (boy) chromosome, research increasingly shows that the environment around the egg - including the mineral balance in cervical mucus, follicular fluid, and blood - can influence which type of sperm is more likely to succeed.

This aligns perfectly with what you’ll read in our Science section:

“The egg and the environment around the egg can have an impact, playing an active role in influencing which sperm succeeds.”

The 2020 study adds even more weight to this idea, confirming that the egg can communicate chemically with sperm and may even reject incompatible ones - long before fertilization occurs.

🌿 How Diet Shapes the Environment

So how do you influence this environment?

That’s where diet-based gender swaying comes in. For over a century, scientists have studied how changes in mineral intake can affect gender outcomes. Research has shown that:

• Higher calcium and magnesium may increase the likelihood of conceiving a girl

• Higher potassium and sodium may favor a boy

By adjusting your diet over several weeks before conception, you can shift the mineral balance in your reproductive tract - effectively supporting one type of sperm over the other.

A Century of Evidence Linking Minerals to Baby Gender

We don’t rely on myths. Our recommendations are rooted in science — with consistent findings across animals, humans, and decades:

🔹 Foundational Animal Studies

• Herbst (1928) – Marine worms in potassium-rich water produced more males; calcium-rich = more females

• Vahidi et al. (2007) – Rat litters skewed male with high sodium & potassium diets; female with calcium & magnesium

• Alhimaidi et al. (2021) – In sheep, sodium/potassium-rich diets = 77% male offspring; calcium/magnesium = 72% female

🔹 Human Studies You Should Know

• Stolkowski et al. (1980 & 1981) – ~80% success in 281 couples using mineral-specific diets

• François Papa (1983) – Published study and book after consulting 200+ women with >80% success in Paris clinic

• Oxford University (2008) – Tier-1 study of 740 women showed high sodium & potassium pre-conception diets led to more boys

• Noorlander et al. (2010) – Dutch study showed diet alone raised girl-sway success to 73%; when combined with timing: 81%

• Edessy et al. (2016) – In Egypt, 72% of women on Ca/Mg diets had girls, 76% on Na/K diets had boys

• Farhud (2022) – Iranian study with 285 women showed gender-swaying success of 83% and 87% in two separate groups

The 2020 study adds an exciting new layer: The egg responds to more than just sperm. It responds to the conditions around it.

🩷💙 So… Is It Really Her Choice?

In a way, yes. The egg is not passive. It listens, it signals, and it selects. Your diet and lifestyle may help create the conditions that support the sperm you’re hoping for.

And that’s the foundation of Sway natural - making evidence-based choices to shape your body’s internal environment in a way that naturally supports your gender swaying goal.

✅ Ready to Sway Smarter?

We’ve built tools and plans to help you take the guesswork out of gender swaying:

• 💡 The Sway Factor Tool: Instantly see whether a food supports a girl or boy sway

• 🥗 Dietitian-Approved Meal Plans: Easy-to-follow, nutrient-rich, and scientifically designed

• 📘 Girl & Boy Food Guides: Packed with research-backed tips and food lists

• 📅 The Sway Tracker: Monitor your progress and stay on track with your sway

✨ Explore your Sway Plan here

Sperm might carry the chromosomes, but the egg makes the final decision. And with the right preparation - through food, timing, and understanding your body - you just might help guide that decision.

Because when it comes to conception, she’s been running the show all along.

Sources:

• Fitzpatrick, J. L., et al. (2020). Chemical signals from eggs select sperm in humans. Proceedings of the Royal Society B

• University of Manchester Summary

• Herbst, C. (1928). Bonellia viridis sex determination via potassium/calcium concentration

• Stolkowski, J. & Lorrain, J. (1980–81). Preconception selection of fetal sex. Isr. J. Med. Sci.

• Papa, F. (1983). Boy or Girl: Choosing Your Child Through Your Diet

• Mathews, F. et al. (2008). Proc. R. Soc. B, Oxford University Study

• Noorlander, A.M. et al. (2010). Reproductive BioMedicine Online

• Edessy, M. et al. (2016). Int. J. Curr. Res. Med. Sci.

• Farhud, D. et al. (2022). Iranian Journal of Public Health

• Vahidi, A.R. et al. (2007). Pakistan Journal of Nutrition

• Alhimaidi, A.R. et al. (2021). Saudi Journal of Biological Sciences