KATHMANDU, Nepal - A recent study of Nepalese men who had been sterilized
with a form of vasectomy (male sterilization) widely used in developing
countries has found that the pregnancy rate is higher than previously
thought. The study included 1,052 men who had had a vasectomy between one
and four years ago.

The study, undertaken by Family Health International (FHI), in collaboration
with the Ministry of Health, His Majesty's Government (HMG) of Nepal,
estimated a first-year pregnancy rate of 17 per 1,000 among wives of men
having ligation and excision vasectomies. That is, among 1,000 couples using
this particular form of vasectomy for family planning, 17 women would become
pregnant during the first year following the procedure. "This contrasts with
an estimated pregnancy rate of 1 to 2 per 1,000 vasectomies in the United
States, where different vasectomy procedures are typical and where couples
are much older," reported Hanif Nazerali, FHI's principal investigator for
the study.

Compared with other forms of family planning, the vasectomy procedure used
in Nepal is still quite reliable. For example, for couples using the Copper
T intrauterine device, considered a very effective contraceptive method,
approximately 8 women per 1,000 users will experience an unintended
pregnancy during the first year. And for couples using condoms,
approximately 30 to 140 women among every 1,000 become pregnant during the
first year.

"This study is unique in that it is the first time that we have attempted to
evaluate the effectiveness of vasectomy in a large sample of men from
diverse areas in Nepal," says Dr. Kalyan Raj Pandey, a research member of
the study, President of the Nepal Medical Association and advisor to the
Ministry of Health.

"The results of the study in Nepal are not very different from what we are
finding in some other developing countries when simple ligation and excision
are used," reports Dr. David Sokal, a medical director at Family Health
International. "While a vasectomy procedure is an excellent method of family
planning, it's important that couples understand there is a small but real
possibility of pregnancy after vasectomy."

"The study findings have important implications for counseling, follow up
and clinical training," notes Dr. Laxmi Raj Pathak, another member of the
research team and director of the Ministry of Health's Family Health
Division.

Vasectomy is a permanent form of contraception in which the vasa deferentia
- the tubes that carry sperm from the testes - are occluded (closed), either
by ligation or other means. In developing countries, ligation (tying) and
excision (removal) of a small length of the vas is the most common method of
occlusion. In the United States and other high-resource settings where
vasectomy is popular, cautery (burning) or metal clips are the most commonly
used methods to occlude the vas.

Family planning handbooks typically describe vasectomy as nearly perfect,
better than 99 percent effective at preventing pregnancy. However, different
ways of performing a vasectomy may result in slightly different pregnancy
rates.

In a related study, specifically designed to compare two different vasectomy
techniques, preliminary results being released later this month show
conclusively that sperm counts decrease more rapidly when a surgical
technique known as fascial interposition is added to the simple ligation and
excision technique. That study was conducted in Nepal and six other
countries. Most of the men in the study announced today in Nepal had
undergone vasectomy using simple ligation and excision, but without fascial
interposition. Fascial interposition is a procedure in which the sheath
covering the vas is pulled over one severed end and sewn shut to create a
natural tissue barrier. The seven-country study looked at multiple sperm
counts in each man, rather than pregnancy rates.

In the study reported today, researchers contacted men who had had a
vasectomy one to four years ago, and asked each of them to provide a single
semen sample for laboratory analysis. The men were also asked whether their
wives had become pregnant. The men in the study were chosen from over 30,000
men who had had vasectomies between 1996 and 1999. The four Hill Districts
of Bhojpur, Doti, Ramechhap and Tanahu were chosen randomly to represent the
Development Regions. A proportionate sample of men was then selected
randomly from within these districts. About 75 percent of vasectomies
performed in Nepal are done in the Hill Region.

Twenty three men, or 2.3 percent, still had sperm in their semen, and 38 men
reported that their wives had become pregnant during the years since their
husband's vasectomy. Pregnancies were more common among the younger women in
the study. Eight of the pregnancies occurred within three months of the
vasectomy, before a vasectomy is considered to be effective. A life-table
calculation gave an estimate of a cumulative pregnancy rate of 4.2 percent
at the end of three years (42 among every 1,000 women) or about 1 percent
per year.

"It is quite possible that the pregnancy rate following vasectomy in the
United States is an underestimate," said Hanif, FHI's principal
investigator. "If couples believe that vasectomy is 100 percent effective, a
subsequent pregnancy would infer infidelity, and may go unreported. We would
need systematic follow-up, with counseling, to improve our estimates."

Most of the pregnancies reported in Nepal were probably due to
recanalization - the body healing itself - rather than surgical errors.
Also, most couples in this study were relatively young compared to couples
having vasectomies in the United States and other developed countries, which
means they would be more fertile than older couples, and would remain
fertile for more years after vasectomy than older couples. The process of
recanalization can begin when sperm from the open ends of the vas leak out
and cause a mild inflammation. This results in a condition known as a sperm
granuloma, which is part of the body's healing process. A granuloma is made
up of white blood cells and other cells involved in the body's healing
process. The healing process can lead to the formation of a honey-combed
"bridge" that can sometimes connect the two severed ends. Viable sperm can
then cross and make their way to the other end.

Recanalization is often not a permanent condition. Often, the "bridge" will
eventually solidify as part of the healing process, and scar tissue
(fibrosis) will close off the recanalization. Simple ligation and excision
appears more likely to lead to recanalization than other vasectomy methods.

In Nepal, where semen testing is generally not available, men are advised to
wait 12 weeks before relying on their vasectomy. Until that time, couples
are advised to use other contraceptive methods, such as condoms.

This study included two special features: (a) rigorous quality control of
the semen testing; and (b) Internet-based data entry. Semen samples obtained
in the Hill Districts of Nepal were preserved and analyzed in Kathmandu, and
then results were validated by a U.S. laboratory. To facilitate data
collection and analysis, this study used an Internet link for data entry,
from Kathmandu to FHI's office in North Carolina, USA. This was the first
study that FHI conducted using the Internet in this way.

This study was supported in part with funds from the U.S. Agency for
International Development.

For more information, please contact:

Dr. Shyam Thapa
Family Health International
Kathmandu, Nepal
(977-1) 245325, 245919

Mr. Nash Herndon
Family Health International
Research Triangle Park, NC, USA
(919) 544-7040, ext 224
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