Retrograde Ejaculation Underlying Cause
Normally, when ejaculation occurs, a small muscle closes the urethra where urine exits the bladder. This forces semen to pass out the end of the penis.
If the muscle fails to close, the sperm can enter the bladder instead. The presence of sperm in the bladder is harmless, since the sperm leave the bladder during normal urination.
Causes of retrograde ejaculation include:
Continue to Retrograde Ejaculation Anatomy
- Aust TR, Lewis-Jones DI. Retrograde ejaculation and male infertility. Hosp Med. 2004 Jun;65(6):361-4. 
- Kamischke A, Nieschlag E. Treatment of retrograde ejaculation and anejaculation. Hum Reprod Update. 1999 Sep-Oct;5(5):448-74.