How do they know that sperm live up to 5 days ??

[itstakingawhile]

Been ttc for quite a while and was just thinking today I hear so often that sperm survives up to 5 days in the woman’s body - but how do they actually know this ? Have they just gone by the average of how long it survives in a lab or have they actually managed to find out for real somehow? I’m just confused how they know !!!! Also I was questioning if every other day really is ok because worrying maybe DH sperm doesn’t last that long ? Although all tests absolutely fine

You can probably look up studies on Google scholar for the answer to that. My guess is that both studies have been done.

I think they means it’s possible, not that it always does.

Presumably enough women had sex and then 5 days later had a smear test or something and they found live sperm in there 🤷‍♀️ we know what the sun is made of not sure how we couldn’t know how long sperm can live inside a vagina.

I think it's based on how long they stay alive in a test tube.

Apparently someone donated their own fallopian tube to science because she was having them removed for contraception, so they checked the 5 day theory and they did find that it was correct. However that is the only instance of it being checked in an actual woman's body, IIRC.

It was on one of the documentaries I watched about conception when I was TTC about 8/9 years ago so I can't remember which one it was, sorry! It might have been The Great Sperm Race. Of course it might have been wrong/out of date. But the actual woman who donated her fallopian tube was on the documentary telling about it.

They can't live for 5 days in a vagina, it's too acidic. It's only if they manage to get to the fallopian tube that they can live so long.

Oh that makes sense then about the donated fallopian tubes I was just thinking how they would know as it seems to be a fact I hear so often but I couldn’t understand how they’d check inside tubes !

They'd take donated parts, but they'd also do lab in vivo studies too.

Depleting the sperm too often means they may not be mature enough to fertilise the egg, that's why they suggest not having sex every day, but also sperm can be too old so a bit of a balancing act.

I think that 5 days is the outlier, that would be the most resilient sperm in ideal conditions.