Hotline officials released the figures yesterday in a move to promote young people's sexual awareness ahead of World Population Day on Wednesday.

After launching the hotline (65876866) two years ago, the No. 411 Hospital of the People's Liberation Army has received about 20,000 calls for consultations and help.

About 45.38 percent of callers are students and 31 percent are migrant women.

"Among the students, 45 percent come from vocational and technical schools, 25 percent from universities, 20 percent from high schools and 10 percent from middle schools," said Dr Yu Dongyan, the hotline director.

"All these girls are aged below 20 and some are younger than 15."

During the two years, the hospital distributed about 10,000 packs of morning-after pills and provided discounted or free medical services and psychological support to 250-odd pregnant young women.

More than 90 percent of the girls came to the hospital with friends or classmates and without their parents' knowledge.

"Summer vacation is a peak season for the hotline, which received 285 calls in the holiday's first week," said Dr Zhang Zhengrong, from the hospital.

"Some girls even claimed they have had relationships with boyfriends without knowing their real names, since they are just Internet friends."

Many girls are ignorant about contraception.

Local youngsters normally enter puberty at the age of 12, a two-year advance on 2004.

Authorities say sex education from both schools and parents is lacking.

According to previous research by the hotline, 79 percent of students said they learn about sex from the Internet and 46 percent criticized school sex-education programs as being inadequate.

"It is very important to teach young people knowledge on reproductive health and proper communication with the opposite sex," said Liu Shusheng, director of the Huangpu District Population and Family Planning Commission.

"Young women should learn to protect themselves, while young men should enhance social responsibility.

"Avoiding the topic will only mislead them."