An embryologist has shared fascinating footage of sperm – showing how she can easily spot “bad” swimmers during the IVF process.
Lisa Lee, a fertility doctor, went viral with the post, which garnered 4.7 million views.
The video shows the medic analysing sperm samples, pointing out the various ways you can see which are healthy and which won’t perform well.
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“There are good swimmers, and then there are bad swimmers,” Doctor Lee said.
“Did you know for a sample to be considered normal, only 4% of sperm needs to be OK?

That’s right – [the] majority of the sample contains bad sperm.”
In the video, the Melbourne, Australia-based doctor peers down a microscope at a sample, before showing how she can determine between the best and worst swimmers.
Showing the samples up close, Doctor Lee explained that sperm with bent necks that struggle to swim straight are “bad”.
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Similarly, she says it is not a good sign when a group of sperm group together, and if the sperm swim in a circle rather than with direction, as reported by What’s The Jam.
Other “bad” sperm had two heads and multiple tails, explained Lisa, who has been working in the field for 16 years.
The clip garnered more than 75,000 likes, with one user commenting: “I WANT TO LOOK AT MY MAN’S UNDER A MICROSCOPE!!!!”
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“Well it makes sense that my husbands sperm couldn’t find the egg because he can’t find anything in the house either,” joked another viewer.
Someone else commented: “It’s truly amazing how everything comes together for us to be born.”

“If I ever date, I’m bringing my guy to the lab first, to see if there’s a future,” quipped one follower.
Another added: “If only it was as easy to tell the good men from the bad men.”
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