By Evelyn Leopold

UNITED NATIONS, June 18 (Reuters) - Calling it a condition too unpleasant to discuss, a U.N. agency on Wednesday urged African nations to end the silence and confront one of the world's worst pregnancy-related disabilities.

Girls and women suffering from obstetric fistula, which results from obstructed labor, endure an uncontrollable leakage of urine or feces that often means being shunned by their family and isolated in a hut.

The U.N. Population Fund (UNFPA) and EngenderHealth, a New York-based international reproductive health group, went to nine African nations to analyze hospital data, public obstetrics information and available treatment as part of a survey to shed light on the problem said to afflict millions.

"We hope this report will sound a global alarm about fistula," said Thoraya Ahmed Obaid, UNFPA's executive director told a news conference. "Most women living with fistula today suffer in silence, unaware that a simple cure is available.

Prevention involves a Caesarean section for delivery and if this is not done, reconstructive surgery, even years after the pregnancy, can cure the condition. The cost ranges from $100 to $400, often a prohibitive amount for impoverished women.

Obaid has appointed her predecessor, Nafis Sadik, a Pakistani physician, as her special envoy on fistula.

The 96-page survey was unable to say how many women suffer from the condition in sub-Sahara Africa. The World Health Organization in 1998 estimated 2 million girls and women are afflicted and another 50,000 to 100,000 were stricken each year. The new study believes the figures are much higher.

In Nigeria alone, the report said, as many as 1 million women may be living with the condition. The other nations surveyed were Benin, Chad, Malawi, Mali, Mozambique, Niger, Uganda and Zambia.

Dr. France Donnay of UNFPA said that requests for surveys have multiplied with Tanzania, Ethiopia, Eritrea, Rwanda, Ghana, Togo and Senegal next on the list.

"Everybody knows somebody who has fistula," she said.

The obstruction usually occurs because the woman's pelvis is too small, the baby's head is too big, or the baby is badly positioned. The baby usually dies and if the mother survives she is left with extensive damage to her birth canal.

"Women are totally stigmatized when they have this problem, said Dr. Amy Pollack, president of EngenderHealth. "They are often rejected by their families and by their spouses -- almost always. They are the survivors."

In some nations women hear of a surgeon and are "willing to walk for days, for weeks, for months, hoping that surgeon will return and change their life," she said.

The condition is nearly wiped out in developed nations. In New York, the last hospital dedicated to fistula closed about 100 years ago on the site where the Waldorf Astoria Hotel now stands, Donnay noted.

African women with fistulas are often under 20, some as young as 13, illiterate and poor. Many live in nations devastated by AIDS, malaria, famine, endemic poverty and years of political instability, leaving public hospitals in crumbling condition with chronic shortages of staff and equipment.

Women treated at the Niamey National Hospital in Niger were strikingly similar. Some 22 percent had experienced some form of female circumcision or genital mutilation, 88 percent were married at 16.

In Mozambique just three physicians treat fistula. Counseling is nonexistent and the perception of women who go to family planning clinics is that they "have more than one man" or they would not need such services, the report said.