When Peggy Lam Pei Yu-dja joined the Family Planning Association as its first full-time executive director in 1961, large broods were the norm, especially in poorer households. Many were refugees from the mainland who crowded into hilltop squatter settlements.
"A family of eight would sleep on the same bed," Lam says. "People coming from the mainland before 1949 were rich investors. But those who came in the 1950s and '60s were destitute. Having children was their only form of entertainment. A big family was viewed by traditional Chinese as being propitious.
"The Tanka [boat dwellers], who made up a large chunk of the population, regarded having another baby as nothing more than adding a pair of chopsticks [to the dinner table]. They saw children as free labour who could help them catch fish."
There was no concept of family planning then and the result was a population explosion that put a severe burden on society, Lam says. By the time she left the association in 1988, not only was birth control widely practised, once-discomfiting notions like pre-marriage check-ups had become routine.
Demographic forces have since swung to the other extreme, with Hong Kong now recording the world's lowest birth rate of 0.94 (Singapore's is 1.3). And as the post-80s and post-90s generations begin to start families now, the association has evolved from being a promoter of birth control to become a promoter of sexual health, sex education - and provider of fertility services.
The association really began in 1936, when a visit by American birth control activist Margaret Sanger, inspired local philanthropist Ellen Li Tso Sau-kwan and obstetrician and gynaecologist William Charles Wallace to set up the Hong Kong Eugenics League. (While eugenics evokes images of controversial social engineering, successors did not know why the name was chosen and the leagues' files were destroyed during the Japanese invasion.)
The league was renamed the Family Planning Association in 1950, and Lam took up the reins about a decade later at Li's invitation. The only full-time staffer aside from doctors and nurses manning its clinic, she had her work cut out for her.
"We had a clinic but no one knew of our existence. The government began to give us money in 1955, but it was just HK$5,000 per year.
"Many households did not have televisions and radios in the '60s, so I went door to door to urge people not to keep having babies. [Older folks] would berate me for asking their daughters-in-law not to have so many children," she recalls.
"We introduced sex education in the '70s, but principals refused to let us into the schools. Education officials didn't help. They equated sex education with promoting promiscuity. Back then we called it family life instead of sex education."
Lam, who studied sociology at the University of Shanghai, had to rely on volunteers and think of creative ways to get their messages across. She introduced the concept of promoting family planning through the mass media, broadcasting television jingles which made the association a household name. The "two is enough" slogan, launched in 1975, was also her brainchild.
"I asked the late Canto-pop lyricist [James] Wong Jim to pen a song and lyrics to go with it as part of our silver jubilee celebrations. He did it in a couple of days, gratis."
"I tried to couch embarrassing concepts like men having a responsibility to wear condoms in pithy slogans with covert sex references. Every child sang them, and their parents picked up the messages by osmosis.
"When they saw the slogans on the street, they smiled as they understood the tacit sex messages behind them," adds Lam, chairwoman of the Hong Kong Federation of Women.
Josephine Lau Yuen-wah was a frontline witness to the FPA's evolution. When she joined the association in 1984 as a field worker, her job was to cajole women to get out from under their husbands' shadows to inform themselves about sexual health and birth control.
"Women were passive then," Lau says. "We had to provide yoga, ping-pong and tutorial classes to lure them out [of the home]."
Her proudest achievement was the establishment of the FPA Women's Club, which whose mission was to identify potential leaders in the community and nurture them to become ambassadors spreading the message of female empowerment, she says.
The first club was formed in 1981 in Tai Po; and it has since grown to a network of seven clubs with more than 10,000 members.
Lau, who took early retirement three years ago, is gratified that women are not only more vocal, they are able to band together to improve their rights. The club set up a drama troupe in 2003 to stage plays as a way to communicate information; for example, on the importance of regular uterine tests or Pap smears.
"The women I came across over the years have transformed from subservient homemakers into intrepid torch-bearers who think nothing of talking about sex, female genitalia and reproductive health," Lau says. "They not only spread ideas around the community, they influence their families. Their children pick up their messages and their husbands come along to support them in their drama performances."
With population growth reined in, Lam initated fertility services such as a sperm bank and artificial insemination in the '80s to help people who had trouble conceiving. But these were scrapped four years ago as advances in reproductive technology reduced demand (there were only 13 couples seeking artificial insemination at its clinic in 2007).
Moreover, better services became available after the Human Reproductive Technology Ordinance took effect in 2007, as many private clinics with hi-tech equipment were licensed to provide artificial insemination, gynaecologist Susan Fan Sun-yun, who became FPA executive director in 1995, explains.
"Our artificial insemination service required a lot of sperm from donors as we did not tinker with the ovary at all. We did not have the facilities to do invasive surgery to extract eggs. We did not make test-tube babies. So [men] with a low sperm count had to rely on donors whose sperm was used to fertilise the egg. Our success rate was just 7 per cent, compared to 40 per cent in outside organisations," Fan says.
After investigating, the association decided it was not cost-effective to upgrade its artificial insemination facilities. They have also stopped providing procedures such as tubal ligation as modern contraception is now convenient, effective and safe, she says. And while its clinic still conducts vasectomies, demand is falling.
"Fewer people go for permanent contraception now," Fan says. "One reason has to do with the high divorce rate. People might want to have babies again after divorce and remarriage. Some want to have the option if they change their mind."
Although the FPA now offers new services such as Pap smear tests, community education and research continues to be a major focus of its work.
Misconceptions about sex are still prevalent, Fan says, so a lot of effort goes in education for young people (mainly how to protect themselves), couples counselling and homosexuality awareness. They also conduct a major survey every five years, the Youth Sexuality Study, which tracks changes in attitude, behaviour and sexual knowledge among young people.
Government figures show the number of pregnancy terminations performed has dropped from 18,651 in 2002 to 11,231 in 2010, and Fan attributes this fall to the success of their family planning education work.
As couples are marrying later, infertility is a growing problem because of poorer ovulation in older women or low sperm quality in men (the infertility rate has risen over the past two decades from one in 10 to one in six).
Despite the birth rate declining to a worryingly 0.93 (a rate of 2.1 is needed to sustain a population), Fan says the FPA won't get into the business of promoting bigger families.
However, it plans to resume artificial insemination services, but this time round use technological advances to make the most of the husband's sperm.
"Sperm concentration technology now allows us to use less to conceive. People always prefer to use their own sperm for the continuation of their family line.
"Now that people are getting married later, there are long queues for private reproductive companies. So we want to continue serving infertile couples," Fan says.
Their mission has always been to give people the chance to make an informed choice, she says.
"Sex and reproduction are issues that concern everybody from the cradle to the grave. Everybody has the right to a choice. They can choose whether to have babies, or to get married."
These days, for instance, women might consider freezing their eggs when they are younger.
"While our focus in the past was to encourage people not to have too many babies, our aim now is to urge people to plan early. Otherwise, it will be too late."