Pre-ejaculate

Origin and composition

The fluid is discharged from the urethra of the penis during arousal, masturbation, foreplay or at an early stage during sexual intercourse, some time before the individual fully reaches orgasm and semen is ejaculated. It is primarily produced by the bulbourethral glands (Cowper's glands), with the glands of Littré (the mucus-secreting urethral glands) also contributing. The amount of fluid that is issued varies widely among individuals. Some individuals do not produce any pre-ejaculate fluid, while others emit as much as 5 ml.

Pre-ejaculate fluid contains chemicals associated with semen, such as acid phosphatase, but other semen markers, such as gamma-glutamyltransferase, are absent.

Function and risks

Pre-ejaculate neutralizes acidity in the urethra caused by residual urine, creating a more favorable environment for the passage of sperm. The vagina is normally acidic, so the deposit of pre-ejaculate before the emission of semen may change the vaginal environment to promote sperm survival. Pre-ejaculate also acts as a lubricant during sexual activity, and plays a role in semen coagulation.

Low levels or no sperm exists in pre-ejaculate, although studies examined small samples of men. Two contrary studies found mixed evidence, including individual cases of a high sperm concentration. There is evidence – dating to a 1966 Masters and Johnson study – that pre-ejaculate may contain sperm that can cause pregnancy, which is a common basis of argument against the use of coitus interruptus (withdrawal) as a contraceptive method.

Studies have demonstrated the presence of HIV in most pre-ejaculate samples from infected men.

Overproduction

In rare cases, an individual may produce an excessive amount of pre-ejaculate fluid, which may be treatable by a 5-alpha-reductase inhibitor, such as finasteride.

References

References

1. Chudnovsky, A.. (2007). "Copious Pre-Ejaculation: Small Glands—Major Headaches". Journal of Andrology.
2. (April 2005). "A neglected gland: a review of Cowper's gland". Int. J. Androl..
3. Vazquez E. (1997). "Is it safe to suck?". Posit Aware.
4. (April 2003). "Short Communication: Does Preejaculatory Penile Secretion Originating from Cowper's Gland Contain Sperm?". [[American Society for Reproductive Medicine.
5. Gohara WF. (1 February 1980). "Rate of decrease of glutamyltransferase and acid phosphatase activities in the human vagina after coitus". Clinical Chemistry.
6. (2011). "Sperm content of pre-ejaculatory fluid". Human Fertility.
7. (2016). "Presence of Sperm in Pre-Ejaculatory Fluid of Healthy Males". J Med Assoc Thai.
8. Masters, W.H.. (1966). "Johnson, V.E.". Little, Brown and Company.
9. (October 1993). "Researchers find no sperm in pre-ejaculate fluid". Contraceptive Technology Update.
10. (1992). "Pre-ejaculatory fluid as potential vector for sexual transmission of HIV-1". Lancet.
11. (1992). "Detection of HIV-1 DNA sequences in pre-ejaculatory fluid". Lancet.