For men with low sperm counts, sexual abstinence - but only for a day - increases semen quality. More prolonged sexual abstinence may actually reduce sperm numbers, a new study indicates.

“After only two days of abstinence, sperm from patients with male factor infertility initiate a process of quality degradation,” Dr. Eliahu Levitas of Soroka University Medical Center in Beer-Sheva, Israel, and colleagues report.

The findings are important for men trying to father children through In-vitro fertilization, or even through the natural method.

Levitas and his team note in the medical journal Fertility and Sterility and Sterility that most fertility clinics likely follow World Health Organization recommendations, which advise men to abstain for 2 to 7 days before semen collection for fertility evaluation. The researchers conducted the current study to determine the effect of abstinence on sperm quality.

The researchers analyzed 9489 semen samples from 6008 men, comparing the concentration of sperm, percentage of normal sperm, percentage of motile sperm, and volume of semen, to the duration of abstinence before sperm collection.

Among the 3506 samples classified as being low sperm counts, peak sperm concentration occurred after 1 day of abstinence and declined thereafter.

Peak sperm motility also was seen after 1 day of abstinence, followed by a gradual decline.

The percentage of normal sperm also peaked at 1 to 2 days of abstinence for low-count men.

Samples with normal sperm counts showed a slight decline in sperm concentration during 2 days of abstinence, followed by a gradual increase to a peak on days 6 and 7. Sperm motility increased after 1 day of abstinence, and remained high through day 7.

Levitas and colleagues conclude that semen should be collected from men with male factor infertility after 1 day of abstinence, for optimum sperm quality.

Seven days of abstinence will improve sperm quality among men with normal semen, the researchers add, but abstinence beyond 10 days is not recommended.

SOURCE: Fertility and Sterility, June 2005.