"Without the SDU, we never would have met,'' says Ralls-Tan, laughing. "We're looking forward to more children. We'll have at least three."
Currently, the average Singapore woman has 1.6 children 2.1 is the rate demographers think Singapore needs to maintain its population without immigration.
But if the imbalance between taxpayers and retirees continues to grow, the government worries that the welfare system will be strained to the breaking point. On the other hand, the government fears that relying on immigration to close the gap will dilute a sense of nationalism in a city-state dwarfed by neighbors Indonesia and Malaysia.
The problem is often stated in terms of national security: Fewer marriages "impede efforts at nationbuilding and may even threaten the country's survival," says one SDU brochure.
Many Singaporeans, though, believe that the SDU's creation was prompted less by the overall drop in the birthrate than the relatively higher birthrate among the country's poorer Malay minority.
The current racial balance about 75 percent Chinese, 15 percent Malay is important to the government.
Singapore's Chinese majority is one reason the state split from its confederation with Malaysia in 1965, following race riots. Lee Kwan Yew, Singapore's founding father and architect of its social policies during his 20 years as prime minister, is closely identified with policies to promote Chinese culture.
To critics, the focus on "educated" men and women today is merely a politically correct way of targeting the ethnic Chinese.
In fact, in the early days of the SDU, the divergence in birth rates across racial and socioeconomic classes was a stated reason for taking action.
"If we continue to reproduce ourselves in this lopsided way we will be unable to maintain our present standards,'' Mr. Lee said in his national day speech in 1984, the year the SDU was created.
Later, in a 1990 speech, Lee said that the preference of educated men for less educated women was a national dilemma because it meant "50 percent of graduate girls will either marry down, marry foreigners, or stay unhappy."