Time to Azoospermia -- September 8, 2003

Research Triangle Park, NC —Typical recommendations on how long men should wait before relying on the most common type of vasectomy in developing countries may need to be revised, according to a new study by Family Health International, EngenderHealth, and the Instituto Mexicano del Seguro Social in Mexico.

Men who have had a vasectomy usually are counseled to use a back-up method of contraception either for 12 weeks (three months) following the vasectomy or until they have ejaculated 20 times. Results from the study, published in the September 2003 issue of the Journal of Urology, show that after use of the ligation and excision method of vasectomy (in which a short segment of the vas—the tube that carries sperm from the testicles to the penis—is cut and removed and the remaining two ends are tied), 12 weeks is a more reliable waiting period than 20 ejaculations. However, neither guideline is ideal, the study reports.

While vasectomy is one of the safest and most effective forms of contraception, it is not immediately effective, because it takes some time for sperm to disappear after the procedure. The best way to determine vasectomy's success is to test a man's semen and show that it does not contain any sperm. But semen testing often is not available in low-resource settings, so many health care providers and men rely instead on a standard waiting period. Some clinics simply give a man 20 condoms and tell him that he can rely on his vasectomy when he finishes using all of the condoms.

But such advice cannot always be relied on, observe the study's authors: "It appears that guidelines for when men can begin to rely on their vasectomy for contraception based solely on time or number of ejaculations after vasectomy cannot adequately replace individual semen testing when ligation and excision are used."

Conducted between June 1995 and June 1996 with support from the U.S. Agency for International Development (USAID), the study included 217 men who received ligation and excision vasectomies at three public health clinics in Mexico City. Semen was then tested to determine how many weeks and how many ejaculations it took for the men to reach azoospermia (the complete absence of sperm).

The number of men who reached azoospermia was nearly 20 percent higher by 12 weeks than by 20 ejaculations. The researchers also estimated that for every 100 men who undergo a vasectomy by ligation and excision, about 60 will reach azoospermia by 12 weeks, while only about 28 will reach azoospermia by 20 ejaculations.

EngenderHealth has already incorporated this finding into its training materials. Its new training curriculum and resources no longer mention 20 ejaculations as a guideline. But they still recommend planning a follow-up visit 12 weeks after vasectomy to confirm success and, whether semen testing is available or not, using condoms or another back-up method of contraception for the same 12-week period.

Yet even though 12 weeks was found to be a better guideline than 20 ejaculations, the time needed for men to reach azoospermia after vasectomy varies greatly. Some men in the study needed as few as two weeks, while others took as long as 24 weeks (six months) or more. "Even at 12 weeks, relying on vasectomy without confirmatory semen testing would involve a risk of fertility for 15 percent of men," the study's authors state.

The research also confirms recent evidence that ligation and excision is not as effective as previously thought. Almost 12 percent of the men were considered to have a failed vasectomy because substantial sperm remained at 24 weeks. But a limitation of the study is that the results were based only on semen testing; it was not possible to estimate the rate of pregnancy among the men's partners. Another shortcoming is that some men who were not azoospermic at the end of the study might have become so shortly afterward.

Nonetheless, the results emphasize how important it is for health care providers and men to know that a small risk of pregnancy still exists after vasectomy, especially when the ligation and excision method is used. Subsequent studies have shown that additional or alternative techniques for blocking the vas can decrease failure rates. These include fascial interposition (in which the fascial sheath covering the vas is pulled over one of the cut ends and the end is sewn shut) and cautery (in which an electrode or hot wire is used to damage the inside of each end of the vas).

To read more information on vasectomy, click here or go to

http://www.engenderhealth.org/wh/fp/cvas2.html.

Source

Barone MA, Nazerali H, Cortez M, Chen-Mok M, Pollack AE, Sokal D. A prospective study of time and number of ejaculations to azoospermia after vasectomy by ligation and excision. J Urology 2003;170(3):892-96.

Family Health International is dedicated to improving lives, knowledge, and understanding worldwide through a highly diversified program of research, education, and services in family health and HIV/AIDS prevention and care. Since our inception in 1971, FHI has formed partnerships with national governments and local communities in countries throughout the developing world to support lasting improvements in the health of individuals and the effectiveness of entire health care systems.

Founded in 1943, EngenderHealth is a nonprofit organization that has been working internationally for more than 30 years to support and strengthen reproductive health services for women and men worldwide. Since its inception, its work has improved the health and lives of more than 100 million individuals in 90 countries.