Does Viagra have any effect on sperm in a man trying to have a child? Does it affect the sperm count, mobility, etc.?

-- Renee

Viagra has no known effects on sperm production, morphology (shape), motility (movement) or count.

If a man has organic impotence -- meaning the problem is due to a medical rather than psychological condition -- then Viagra may improve the chances for achieving conception simply by restoring potency. Remember, though, that while Viagra can improve rigidity, it does not necessarily bring about ejaculation. Many men with impotence may have diabetes or other conditions that affect the penis. In this situation, the muscular sphincter that constricts to help ejaculate the sperm may not close properly. In such a case, retrograde ejaculation occurs: The sperm are shot into the bladder rather than out through the penis to begin their journey to find an egg. For more information, see my column on No Semen Comes Out during Intercourse.

If your partner is concerned about his fertility, I would suggest that he consider a semen analysis, regardless of whether Viagra helps his performance. If he has psychological impotence, counseling may be very helpful to ensure that pregnancy is advisable.