However, even if the penis is withdrawn before ejaculation, pre-ejaculate fluid may contain sperm cells that can cause pregnancy and it may also contain organisms that cause ... As the pre-ejaculate leaves the body, however, it may pick up sperm from a previous ejaculation that remains in the urethra. read more
Bob, there are three studies, all small, and in none of them were there any motile sperm in pre-ejaculatory fluid. [i], [ii], Ilaria G, Jacobs JL, Polsky B, Koll B, Baron P, MacLow C, Armstrong D, Schlegel PN. Detection of HIV-1 DNA sequences in pre-ejaculatory fluid. Lancet 1992;340: 1469. read more