h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

A woman in work insists that conception occurs immediately after ejaculation. I am sure that up to several hours can pass, depending on the location of the ovum. (I believe that it can be much longer in the cases of some animals, but I don't know about humans.)

Who is right? What is the average time between ejaculation and conception?

You're right. From what I remember from the "human sexuality" class I took in college, the average is a few hours -- although it can be somewhat quicker, and can also take as long as several days.

i have to admit, I'm somewhat curious as to what the point of that discussion was.....


Mikey

It's not instantaneous. That's one of the reasons the rhythymn method fails easily. Intercourse several days before ovulation can result in a pregnancy - take it from me!

I do remember reading that sperm can survive for up to three days inside the body - cos it's nice and warm etc...
Couldn't be instantaneous conception though cos they have to travel quite a way. Presuming that the ovum was in prime position it must still take at least an hour or so, I would've thought.

I suppose it depends how frisky they are.

The moment of conception is when a male gamete (sperm) succeeds in stabbing through a female gamete (ovum) to produce a zygote - and not before. When conception occurs is all a matter of distance; if the ovum is still in the fallopian tubes, it will obviously take longer than if the ovum is practically in the uterus. Also, if the sperm are sluggish, then it'll take longer than if you've got super fast-moving sperm.

Thank you for your answers. Mikey the Humming Mouse wondered why I asked this question. Well, here goes...

Seeing a pregnant woman at work made me think about the actual moment of conception - the father could be hours away at the time. If both parents got in high-speed rockets and flew away from each other as fast as possible then the distance would be quite large. The mother would always be at ground zero at the time of conception. However, how quickly would the man become a father - i.e. how fast does fatherhood travel? If it is instantaneous then we have FTL communication of this fact to the man's location.
Attempts to measure the speed of fatherhood would be easier than that of motherhood since there could be a significant distance involved. Presumably the moment of fatherhood hitting the man is measured by a sudden drop in IQ and increase in emotional instability. It seems fair to postulate that motherhood travels at the same speed as fatherhood, although this is not necessarily so.



P.S. Don't worry - I am receiving treatment for my condition.

This discussion put me in mind of the Boris Becker paternity suit where he was accused of 'fertilizing' a woman in a broom cupboard in the (appropriately named) 'Nobu' restaurant. Without getting too graphic (and offending the moderators), Becker claimed that intercourse itself had not taken place (Clinton style) and therefore could not be the father. However the woman said she had impregnated herself (later on) - those who read about the case know what I'm referring to, those who didn't will have to use their imagination.

Anyway Becker was found to be the father, but presumably (according to him) conception took place while she was in the Ladies loo and he was wizzing down Park Lane in a black cab.

Anyway the whole incident gave us a good laugh....