Growing numbers of people are seeking help from the Family Planning Association because they do not know how to have sex. Grace Wong Ching-yin, who heads the fertility service, said: 'Some married couples are not familiar with their body parts. They don't know where their sex organs are.' Dr Wong said there were some couples who did not know the procedures involved in sexual intercourse. 'They do not know the physical changes associated with sexual response, like males having erections.' As well as a lack of knowledge, some couples have psychological problems associated with sex. 'Some believe sex is dirty,' explained Dr Wong, adding that this could be due to their past experience or religious beliefs. Dr Wong said couples who failed to successfully have sex on their first night often became stressed in their later attempts to get more intimate. The association says such people made up a significant proportion of the 1,578 people who sought help from them last year - a jump of more than 50 per cent on the 1,047 in 2003. Emil Ng Man-lun, one of the city's best-known sexologists, said he had seen plenty of cases of couples who did not know how to have sex. Professor Ng, of the University of Hong Kong's department of psychiatry, was not surprised by the lack of sex knowledge and blamed it on poor sex education in Hong Kong. 'Current sex education rarely touches on sexual techniques. If touched on, it is not detailed enough to be useful,' Professor Ng said. He said some religious groups taught people that sex was dirty. 'For example, they teach that virginity is pure and that being asexual is saintly. Some parents scare their children away from sex in order to protect them from getting into trouble.' Dr Wong said many couples with fertility problems were ignorant about surrogacy. The South China Morning Post last month revealed that former legislator Christine Loh Kung-wai and her partner, Craig Ehrlich, had become the parents of a baby girl, Leah Norma Ehrlich, born in the United States from an egg donated by a Chinese woman but carried by a third woman. Dr Wong said the association would not comment on this case - the city's first surrogate baby - or any individual cases. She said most couples were able to solve their problems after consulting the association. People seeking help on family planning issues can call the association's hotline at 2575 4477.