Aside from the hilarous responses on yah.oo answers to "how long does sperm last within the human body?" (my favorites were "too long!" and "two days if you are trying to get pregnant, five days if you don't want to get pregnant"), I found this delightful article about Sperm Transport in the Female Reproductive Tract. I love that! All those little sperm thinking, what kind of transport should I use? Should I catch the bus? Or ride my teensy sperm-sized motorbike?
And a bonus - the article features a picture of sperm nestling into a "ciliated area of Fallopian tube epithelium" - please tell me this doesn't remind you of Nemo hanging out among the fronds of the sea anenome? (the white arrows point to the heads of the sperm)
Image from here.
I was reading out bits of this article to El Prima, and told her sperm had a usual swimming speed of 5mm per minute, and she said, that's faster than Ian Thorpe. Indeed it is. Given that sperm are only 5 microns in size (admitedly not including their tails), it would be like Ian Thorpe swimming at 1200 km per hour!
The upshot is, who knows. Who knows whether they got there in time, who knows whether they survived long enough. I got sad news yesterday that my friend doing IVF had a negative blood test - and am hoping the little fertility charm works for her next time. We're still waiting for our lottery ticket to be called, but in the meantime, I'm distracting myself with all these scientificky words:
In the uterus, muscular contractions may enhance passage of sperm through the uterine cavity. A few thousand sperm swim through the uterotubal junctions to reach the Fallopian tubes (uterine tubes, oviducts) where sperm are stored in a reservoir, or at least maintained in a fertile state, by interacting with endosalpingeal (oviductal) epithelium. As the time of ovulation approaches, sperm become capacitated and hyperactivated, which enables them to proceed towards the tubal ampulla. Sperm may be guided to the oocyte by a combination of thermotaxis and chemotaxis. Motility hyperactivation assists sperm in penetrating mucus in the tubes and the cumulus oophorus and zona pellucida of the oocyte, so that they may finally fuse with the oocyte plasma membrane.
So now I've got scientific evidence that fertilization can occur when the sperm arrive "up to five days before ovulation". Which leaves me singing my strangely hopeful little song, "Who knows, who knows who knows who knows".
Am giggling at the yahoo answers. Even dh laughed (and he is unimpressed by my ttc obsessions!)
ReplyDeleteYou know, the ones still alive will have been right there in the playing field when the egg arrived. So you know, hang in there :)
I was looking at sage flower buds and thinking of you today, crossing fingers and hoping. x
ReplyDelete(PS My security word today was 'struessel' - do think that's a sign we need cake?)
Who knows who knows indeed. But crossing my fingers for you. And thinking it's awesome how fast they swim, and that picture is neat, but creeps me out to think of that inside me.
ReplyDeletefingers crossed! i know people have gotten pregnant from what they thought were ill-timed IUIs. do you guys use fresh sperm or frozen? i hear the longevity of fresh sperm is pretty damn amazing.
ReplyDeleteFingers crossed for you. You have a gift with research (I guess that is part of the excellent teaching skills). I love the photo, and hope that El Prima was good by helping induce some of those muscular contractions to aid the spermies to get to wehere they needed to be....
ReplyDeleteI'm totally laughing at that last response to yahoo answers. And I have to say that those fimbriae look really comfortable.
ReplyDeleteWishing you luck.
Good luck!
ReplyDeleteCrossing my fingers for you!
ReplyDeleteimagine how fast they'd be in those speedo bodysuits! good luck!
ReplyDeleteAt first glance, I was unimpressed. 5mm per minute. Where's your hustle? But turns out they are really speedy little guys when you think about it!
ReplyDeleteArgh, so much of that which is important in life comes down to 'who knows'. Wishing you the very best of luck and thanks for brightening up my day with the assorted sperm facts!
Fresh sperm has so much more staying power, I think. Fingers crossed for you!!!
ReplyDeleteI laughed at the yahoo answers.
Who knew sperm could be so amusing!
ReplyDeleteThank you so so much for all the good luck wishes and giggles!
@pomegranate - Yes, we used fresh. I'd forgotten how MUCH there is of it compared to frozen. Eek! It was fresh that worked last time (after 9 failed frozen insems) so we're going to try and line up as many fresh insems as possible.
@Schro - yes, El Prima did a very admirable job in that department. ahem!
@brianna - fimbriae? Clearly you're a scientific word nerd too. I just love the sound of endosalpingeal fimbriae.
@ping - it is always struessel-time with me!
@Catherine W - exactly right - we're at the mercy of so many things beyond our control. And I'm glad to know I'm not the only one who finds reading about hyperactivated sperm to be calming and uplifting!
xxxxxxxh
lol, well, this month I turned out to be mostly at the mercy of my body going for it a week early and my husband being NOT IN THE MOOD. So... where d'ya get fresh sperm? ;)
ReplyDeletei think 4-5 days is fine!!!
ReplyDeletexxxxk
@ Merry - that's bad luck. We've got a known donor we met about 4 years ago who lives in Sydney. His job takes him out of the country pretty regularly, but we were lucky that our schedules sort of matched up reasonably well for october and november. He's lovely, and has been very flexible - flying down to melbourne or meeting up with us in Sydney as needed.
ReplyDelete@ k - hope so! xxxh
Ahh yes. Good old Dr Google. you sound just like me, I know FAR MORE than I really need to know about reproductive science.
ReplyDeleteFWIW, I was CONVINCED that there was no chance I could get pregnant with our little because our insems were so far out from ovulation. However, two weeks later I discovered otherwise ;) Hope you have the same luck!
Great electron microscopy picture! And the irony of those Google responses is great :)
ReplyDeleteI still find it amazing that cells like sperm can move so dramatically. Neurons can do the same - they really get going inside the brain once a little one is growing in utero!
I guess by now you have an outcome.. I have been thinking of you lots. xx
Oh, and I also have an auspicious security word.. 'making'
Hey L - yep, not the outcome we wanted, but an outcome nonetheless. Thanks for lovely thoughts and auspicious words.
ReplyDeleteI'm very curious about the neurons - do you mean inside the mama brain or inside baby brain?
xxxh
I mean inside the baby's brain. Many neurons are born in one part of the brain and migrate to their final destination - not only to the right part of the brain, but the right layer of cells within that part, all on the basis of internal cues that act like molecular beacons - people do experiments with neurons in vitro and you can see them moving along quite rapidly (if 10 - 20 microns per hour is rapid - it's not, compared with sperm!). There's some new thinking that if this migration is stopped too early due to some genetic aberration or other event, it might explain the cases of schizophrenia where the brain has fewer of the 'right' types of neurons in place.
ReplyDeletewow - is amazing! You do wonder whether it might not be a bit simpler just to grow the right brain cells in the right place, but then efficiency doesn't really seem to be nature's strong point. Is this part of the whole 'brain plasticity' debate - whether these neurons get to the right spot and then stop or whether they keep migrating?
ReplyDelete