time it takes for sperm to penetrate egg?

[gizmo77]

once your egg pops out, obviously there is only 12-24 hrs for sperm to locate and fertilize before egg dies...but how long does it take for sperm to actually find and fertilize an egg? or just fertilize?

[Hobbermittens]

I wonder this too. Thanks for asking! I will keep watching this thread for the answer.....

[rainbowflower]

it depends if the sperm is already there waiting or not. I read somewhere ages ago it can take less than an hour if so... but if it's a "fresh deposit" the sperm would need to capacitate before it can penetrate the egg and I don't know how long that takes

[nuthinbutpink]

Check out this-

http://www.embryology.ch/anglais/dbefruchtung/weg03.html

Take a look at the 2 pics-
Fig. 29, Fig. 30
These are monitor screen images from an instrument which records the movement paths of the sperm cells heads (white points) during a certain time span and displays them with a green line. Before capacitation the majority of the lines are straight. After capacitation almost all the sperm cells have now gone over to swinging their heads strongly as indicated by the jagged lines.

Might explain why those that choose to use the microscope see some straight line sperm and some that appear to be moving in circles!

Capacitation is the change in the sperm head membrane that prepares it for fusion with the egg membrane. Sperm have to undergo capacitation in the female reproductive tract before they are able to fertilize the egg. Capacitation is facilitated by the cervical mucus, and it usually takes several hours after ejaculation before the sperm can fertilize the egg. Sperm that reach the egg within minutes after ejaculation did not have enough time to undergo capacitation, and are less likely to be able to fertilize the egg.

The above might explain why it takes you guys TTC a girl longer to get pregnant if there is no cervical mucus to help out the sperm(there is always some and it doesn't take much!).

[gizmo77]

i guess i wanted to know a) how long does it take for a sperm to travel to our tubes and b) ho wlong does it take for one sperm to finally fertilize/fuse with the egg (for sperm that was waiting there for an egg).

thats interesting reading nbp. esply the part about if the sperm gets there too fast and no time to capacitate. so technically, it IS best for both girl and boy sways to DTD BEFORE ovulation. if you do it right at ovulation, theres a chance the sperm wont have enough time to capacitate and fuse....

[nuthinbutpink]

Fast swimming sperm, 30 minutes. They can live 48-72 hours though so it can take that long.

Fertilization takes 24 hours.

[rainbowflower]

gizmo - yep, another reason why O+12 is even more risky especially if your egg doesn't quite last the 24hrs as many don't

[atomic sagebrush]

Thanks guys, great answers as always. I really don't have a lot to add to this thread other than that I've read that the fastest sperm are not only uncapacitated, but usually dead on arrival anyway (they have nothing left to fertilize the egg because they swim so fast) and that the majority of sperm are actually brought to the egg by the currents of EWCM and not by the action of the sperm swimming. The sperm do swim, but it's more to get past obstacles and to make it from the VJ into the cervix.

I have always believed that of all the people on the planet, virtually all were conceived from sperm already there and waiting for the egg in advance. EVERYTHING about the design of the female repro tract points to this being a truth. That's why I am not a huge fan of either the traditional "one shot at O" timing for boys and O+12, because I think it hinders people from getting pg.

[gizmo77]

this is great info. i was wondering then tho, in couples diagnosed with "unexplained infertility" what do you guys think is the problem? too fast sperm not capicitating? so im talking about a woman with healthy eggs who ovulates every month and a man with a high amount of sperm with good mobility andmotility mortality (isnt that what "unexxplained fertility" is?) everything IS right but it just really isnt enough. the answers ive come up with are hostile environment (repro tract is just denying everything foreign, hostile uterus, same concept, or dna's dont match up (genetic imbalances?).

[nuthinbutpink]

How do you know she has healthy eggs? Genetic issues, uterus issues, timing, bad sperm for sure to name a few reasons.

[carmella_marie]

I seem to remember from bio class that average sperm swimming at a speed that allows proper capacitation is 4 hours from the time DH ejaculates to reaching the physical location of the egg. Once the egg and sperm meet, the egg instantly stops being receptive to other sperm so that not more than one sperm can fertilize an egg. It takes a little while for the sperm DNA and the egg DNA to mix and start to travel down the fallopian tubes toward the uterus, but if a capacitated sperm and unfertilized egg meet, "fertilization" is pretty instantaneous.

[gizmo77]

How do you know she has healthy eggs? Genetic issues, uterus issues, timing, bad sperm for sure to name a few reasons.

this is just hypothetical. altho i have a couple friends who are diagnosed with this..no reason. im tlaking about if timing is good, they tested eggs (can u do that? lol) tested sperm, she defly ovulates..they tried iui, etc, didnt work. tryingfor 3 yrs.

[gizmo77]

I seem to remember from bio class that average sperm swimming at a speed that allows proper capacitation is 4 hours from the time DH ejaculates to reaching the physical location of the egg. Once the egg and sperm meet, the egg instantly stops being receptive to other sperm so that not more than one sperm can fertilize an egg. It takes a little while for the sperm DNA and the egg DNA to mix and start to travel down the fallopian tubes toward the uterus, but if a capacitated sperm and unfertilized egg meet, "fertilization" is pretty instantaneous.

yeah i remember some of this!

[atomic sagebrush]

this is great info. i was wondering then tho, in couples diagnosed with "unexplained infertility" what do you guys think is the problem? too fast sperm not capicitating? so im talking about a woman with healthy eggs who ovulates every month and a man with a high amount of sperm with good mobility andmotility mortality (isnt that what "unexxplained fertility" is?) everything IS right but it just really isnt enough. the answers ive come up with are hostile environment (repro tract is just denying everything foreign, hostile uterus, same concept, or dna's dont match up (genetic imbalances?).

I think doctors know about 1% of everything there is to know about the human body, esp. where fertility, genetics, and immune system function is involved.

Also wonder if blood glucose could have something to do with it.

[gizmo77]

so is the concensus that pregnancy is most likely to occur if you DTD a day before O verse ON O day or close to O. bc sperm needs time to make its way to egg and capacitate?

[Hobbermittens]

Gizmo!! Are you knocked up?

[gizmo77]

so far yes hobber..we'll see ifit sticks!

[HopeandDreamG]

Hey Gizmo... Just saw your siggy with BFP from yesterday!!! How exciting CONGRATS :).

[Hobbermittens]

so far yes hobber..we'll see ifit sticks!

AWESOME!!! CONGRATS!!! I just saw your siggy too--didn't notice it when I asked the question.... did you post your sway? How many times did you end up DTD and what was your timing??

[atomic sagebrush]

so is the concensus that pregnancy is most likely to occur if you DTD a day before O verse ON O day or close to O. bc sperm needs time to make its way to egg and capacitate?

I personally believe this to be true. I am not sure if I have data to back that up, my brain is whispering that I do but I can't find it on first glance.

The one timing study that I like has equal numbers of conceptions taking place when the last BD took place on O-1 as it does when the last BD is on o (so they prob. BD several times, just that the last one was either O-1 or O) and that makes me think that conception from BD on O-1 HAS to be at least as and probably more likely to conceive than BD on O is.

PS - HUGE congrats Gizmo!!!

[gizmo77]

Hey Gizmo... Just saw your siggy with BFP from yesterday!!! How exciting CONGRATS :).

thanks hope! still debating about when to make a drs appt..i feel like i can wait till like 12 weeks this time..just want to make sure it sticks!

[gizmo77]

AWESOME!!! CONGRATS!!! I just saw your siggy too--didn't notice it when I asked the question.... did you post your sway? How many times did you end up DTD and what was your timing??

yes hobber, i did post my sway. im trying hard to remember details..hard to remember this bc its the 2nd attempt and bc of holidays and numerous parties, my memory (and diet) had been off. and i JUST updated the siggy last night which is why u prob didnt see it before.

i ended up dtd'ing 3 times in a row. my O was late (expected on cd17 as usual) so my intentions were to dtd 3 days in a row with last dtd on O day. so i did O-4 (full moon; cd15) but then no sign of O till +opk on cd18. so dtd on cd 18 (O-1) in the afternoon, then later in the day ihad really good quality ewcm and i just couldnt pass it up so i forced dh to do me again! haha. so 2wice in one day like only 9 hrs apart, and then on cd 19 (the next day; O day) at night (about 24hrs since last bd). i had major O pains that day like never before and was worried dh couldnt perform bc of all the dtd'ing but we worked it out thank god. i know this isnt typical "boy" timing but i couldnt wait anouther month. whens your next attempt?

[gizmo77]

thx atomic!