My wife's ob told us to have sex every other day and or wait 2 days so I could "replenish my swimmers" .
Took that advice and she's 30 weeks.
I wonder what the science is behind that advice. Certainly, after ejaculating there will be a peroid during which the number of sperm you have stored up ready to go will be increasing and, to start with, even the oldest ones will still be viable. There will come a point, of course, when the oldest ones will start to get past it so the number of viable sperm will tend to reach a plateau.
My suspicion, thought, is that this more relevant to the one night stand situation where you meet a woman who happens to be at the optimum point in her cycle for conception and thus he chance of success will depend on how many you can put in on that isolated occasion.
When it's your wife, and you can have sex more than once, I am not sure if makes so much difference as the sperm can survive for a few days waiting for the egg to appear. That worked for us - with our first daughter we were on holiday, which no doubt helps with low stress, and the first week my wife was really horny and that seemed to build through that week. We had sex every day and by the Saturday (the last day of that first week) she was complelely wild. The following day she wasn't horny at all but by then we had obviously done it as two weeks later, no peroid and shortly after that, positive test.
So, I think part of that is also that she can be in touch with her body in that way.
