Pre-ejaculate fluid: All Info?

Alright there are quite a few of these questions on Yahoo! and on the internet, but the answers they get are always mixed and rarely cited. I want to condense these into one question here at Yahoo, so that I can hopefully get some answers. Please cite in anyway if you can... :)

Does pre-ejaculatory fluid contain sperm if (the keyword being if) urination has recently occurred?

How long can any of these sperm that are in the pre-ejaculatory fluid actually survive in the female tract? (Remember that semen has a different composition than the Cowper's Gland fluid)

Yes, pre-ejaculate can and does contain some sperm, not alot compared to a full sample, but still enough to get a woman pregnant if the environment is right. Pre-ejaculate occurs to clean the urethra out of urine crystals which form there which is an acid. Sperm in any sense, can survive in the female body for about 72 hours. Pre-ejaculate typically doesn't contain enough of the other fluids to sufficiently protect the sperm on the journey, but differences in the women or the mans chemistry may make it easier for them to survive the trip as well.

Semen/sperm can be found in urine after having sex, but shouldn't be found there on a normal basis. If it is there are some sphincters not doing their job, which could cause some sterility issues or worse conditions. Urine is extremely acidic and sperm can't survive in it or if any gets near it.

Yes it can contain sperm. That is why the withdrawl method of contaception does not work. The pre-ejaculate gets in and can impregnate.
You have to realize that it does not matter when urination has occurred as sperm will be present in all of the duct work of the male. You can look at your urine under a microscope and you will see sperm.

it will stay active within the female for about 72 hours

yes pre-ejaculate does contain a small amount of sperm but still enough that it could cause pregnancy, go to this site and read about it. talksexwithsue.com