More than 80 percent of adults in China have misconceptions about contraception, according to a survey by the All-China Women's Federation.

The survey was released on Wednesday by Huakun Women's Life Survey Center, which is administered by the federation. Tuesday is World Contraception Day.

It was based on questionnaires from 2,378 males and females aged 20 to 40 from all the country's provinces, municipalities and autonomous regions, and the Hong Kong Special Administrative Region, said Liu Ping, deputy chief of the center.

Of those surveyed, more than 36 percent said they used withdrawal as a means of contraception, which is ineffective.

Nearly half of the respondents said they believed it is absolutely safe to have sex during a woman's menstrual period, and 5.5 percent believed a female cannot get pregnant if the male didn't reach orgasm during sex.

And 3.7 percent of respondents said a woman will not get pregnant if she takes a shower immediately after sex. Nearly 2 percent believed a woman will not get pregnant if the couple stands during sex.

Education and marriage status didn't guarantee knowledge. More than 53 percent of those surveyed hold a bachelor's degree or above, and about 90 percent of them said they are married or have one partner.

More than 17 percent said they or their partners have had an unwanted pregnancy in the past year, and more than 18 percent said either they or their partners had abortions in the past year.

About one-fourth of those said they had no knowledge of oral contraception pills at all, and only about 6 percent said they had ever used them.

"Lack of knowledge of contraception among young people in China can lead to safety risks, including rising numbers of abortions," Liu said. "We are also sorry to see that women in China generally fail to take active contraceptive measures."

Li Jian, a gynecologist at Beijing Obstetrics and Gynecology Hospital, said lack of knowledge about conception - and preventing it - among the general public has been a major cause of unwanted pregnancy and abortion, which can lead to infertility.

Using condoms properly, taking contraceptive pills or using intrauterine devices can be very effective, Li said, while some actions, such as withdrawal, don't work well.

Wang Qiaomei, an official at the National Health and Family Planning Commission's department for women and children's health, said China has been supplying free contraceptive devices and pills and contraception has been included as part of the government's basic public health service programs.

"Medical institutions should provide more contraceptive advisory services to promote the knowledge of contraception," she said. "We also call on individuals to place more importance on contraception to protect themselves and their family."