Journey of Sperm

The journey of sperm begins with ejaculation. Sperm are deposited high in the vagina, close to the cervix and the opening into the woman’s womb. From a sperm’s perspectives the vagina is a very hostile place. That’s why women release only one egg per month, but men unleash millions of sperms when they ejaculate. If a man produces too few sperms, he is under a higher risk of infertility.

So what are the many pitfalls and hazards the sperm encounters along its way inside a woman’s body?

Professor Allan Pacey takes us through the entire journey a sperm has to make in order to fertilise an egg: from the vagina and cervix, through the womb, and into the Fallopian tubes. The Great Sperm Race series explains this journey and why only one sperm can “win”. Read more to understand why the timing of intercourse and quality of sperm are so important when you are trying to conceive.

The Great Sperm Race Part three – The Fallopian Tube

By | May 1st, 2015|

Once sperm reach the relative safety of the Fallopian tubes, their journey to the egg is nearly over. However, success at this stage will rely on precision timing and the abilities of sperm to detect subtle cues and signals from the woman’s body and the egg. Their job is not quite done. It is interesting to think about how many sperm actually get this far. Of the many millions that a man might ejaculate into his partner’s vagina, perhaps only 50 sperm will actually cross the threshold into the Fallopian tubes. This may seem very wasteful, but those sperm that [...]

The Great Sperm Race Part two – The Womb

By | April 24th, 2015|

For a sperm to fertilise an egg, they have to travel a distance of about 10 or 12 centimetres from the vagina to half way along one of the woman's Fallopian tubes. We have all seen films and cartoons of sperm madly swimming to get there in some kind of race, but is it really like that? For those sperm that are able to get through the thick mucus of the cervix (see Part one of The Great Sperm Race), their next challenge is to navigate through the woman's womb and find the opening to one of her Fallopian tubes. [...]

The Great Sperm Race Part one – the Cervix

By | April 24th, 2015|

Have you ever wondered why men need to produce so many sperm? Women typically release only one egg per month, but when men ejaculate many millions of sperm are unleashed. If a man produces too few sperm, then his risk of infertility increases markedly. To understand why, we need to take a closer look at the journey sperm have to make inside a woman's body and the many pitfalls and hazards they will encounter along the way. The journey begins with ejaculation. At the climax of intercourse, sperm are deposited high in the vagina, close to the cervix and the [...]