More married couples are seeking help to get pregnant, prompting the Family Planning Association to offer subfertility treatments at fees lower than those in the private sector.

The association's Wan Chai centre started providing a service in "artificial insemination for husbands" this month - using the man's semen - for couples with difficulty getting pregnant.

The technique involves "washing" the husband's semen - a process that separates individual sperm from the seminal fluid to find the most active sperm - and inserting it into his wife's body. It also involves stimulating ovulation with oral medication.

The technique was already available in hospitals, but the association decided to introduce it in response to increasing demand from clients, it said yesterday.

The demand has increased about 30 per cent in three years, from 4,500 clients attending its subfertility service in 2008 to some 6,000 in 2011.

Dr Emily Lam Po-mui, a private specialist in obstetrics and gynaecology, says she has also seen more couples seeking help in recent years.

"It's usually because people get married and plan for babies at an older age these days," she said. "Also, more people now know about the technology and are less reluctant to seek help.

"In women, it's usually the age problem. In men, there are studies showing that their sperm quality has deteriorated."

Artificial insemination for husbands costs about HK$7,000 in the private sector, including HK$2,000 for the insemination procedure.

By comparison, the association charges HK$1,200 for the procedure; other fees depend on doctors' charges and the laboratory the client chooses for sperm washing.

The pregnancy rate for each treatment cycle is between 8 and 11 per cent.

Results of up to 40 per cent success can be achieved by in vitro fertilisation of women between 20 and 30 years old. The IVF process costs HK$80,000 to HK$100,000 in the private sector.