Mathematicians reveal secret to human sperm’s swimming power

Mathematicians reveal secret to human sperm’s swimming power

How does a sperm get enough power to swim to the egg?

 

A human sperm will have to travel a total of 10cm from the cervix to the fallopian tubes. This may not sound like a huge distance, but for a cell the size of a sperm, it’s equivalent to a human walking from Sydney to Perth and back again… If that doesn’t make you feel exhausted, now imagine it’s a race!

Researchers from the Universities of York and Oxford have discovered that a reinforcing outer layer that coats the tails of the sperm help give them the strength to make the powerful rhythmic strokes needed to travel to the egg.

Out of the millions of sperm ejaculated into the vagina, only around 15-100 successfully embark on the treacherous journey to fertilise the egg, swimming through the reproductive tract and through thick cervical mucus to reach the egg. The researchers revealed that sperm in mammals has evolved to have a reinforced outer layer to give them the extra strength and stability needed to help break through the thick fluid barrier they face.

“We know that, just like in our arms and legs, sperm have tiny muscles which allow their tails to bend — but nobody knows how this is orchestrated inside the tail, at the nano-metric scale,” said Dr Hermes Gadêlha from the Department of Mathematics at the University of New York.

“Sperm are an archetype of self-organisation — movement seems to be happening automatically, perhaps because of a complex combination of many mechanisms at play.”

By understanding the physiology behind this, it could enable fertility clinics to improve their sperm selection methods and therefore improve success rates for their patients.

For more information on male fertility, learn about our treatment options or visit our guide to what normal sperm should look like.

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FAQs about improving natural fertility

Will stress affect my ability to get pregnant?

Yes, chronic stress can impact fertility by disrupting hormonal balance and ovulation patterns. Managing stress through relaxation techniques, regular exercise, adequate sleep, and mindfulness practices may help optimise your chances of conception. Consider speaking with a counsellor if stress feels overwhelming.

How does my partner's health affect our fertility?

Sperm health accounts for about 40% of conception challenges. Your partner can improve sperm health by maintaining a healthy weight, avoiding excessive heat exposure (hot tubs, saunas, tight clothing), limiting alcohol, quitting smoking, managing stress, and taking a multivitamin with antioxidants. Sperm takes about 3 months to develop, so lifestyle changes need time to show results.

When during my cycle am I most fertile?

Your fertile window typically spans 5-6 days, ending on ovulation day. For a regular 28-day cycle, this usually falls between days 10-15, with peak fertility 1-2 days before ovulation. Track your cycle using ovulation predictor kits, basal body temperature, or cervical mucus changes to identify your unique pattern. Having intercourse every 1-2 days during this window optimises your chances.