SINGAPORE - The stork may have become a more regular visitor here as the number of citizen births climbed to 33,193 last year, but experts say it is too soon to tell if Singapore is out of its slump in birth rates.

"It is still too early to say if this will lead to a meaningful and sustainable pick-up in fertility and the number of births," said Institute of Policy Studies research fellow Christopher Gee. "But there are other indicators pointing towards a possible improvement."

The rise in number of marriages, for instance, suggests that more couples are on their way towards starting a family. The 24,037 marriages last year involving one Singapore citizen was the most since 1997.

The total fertility rate in 2000 was 1.6, but there has been a marked slide since then.

The 2014 rate of 1.25 was a welcome reprieve, and expectations are that there will be a bumper crop of babies in this year of Singapore's Golden Jubilee.

But the birth rate will remain well below the replacement rate of 2.1 births per woman despite recent spikes, said National University of Singapore sociologist Tan Ern Ser.

This means Singapore will continue to grapple with the problems of a greying population, and will need to replenish its stock of young people and encourage seniors to stay healthy and to learn to support themselves, he added.

Noted Mr Gee: "We have not seen anywhere else in the world a society with ultra-low fertility - a total fertility rate of less than 1.4 - succeed in moving the rate back towards replacement level."

Significant socio-economic changes would be needed to achieve this, he said.

This includes the age at which couples get married and the age at which women have children, with both moving towards the early 20s.

But a report on population released on Wednesday (Sept 30) by the National Population and Talent Division shows the trend here is the reverse.

The median age of Singapore citizen mothers when they have their first child was 30.3 last year, up from 29.2 a decade ago.

And men and women are getting married later. For men, it is now 30.1 - up from 29.4 in 2004. It is 27.9 for women, up from 26.3.

PM Lee noted in a speech earlier this year that if the total fertility rate stayed at 1.2, "then I think that is going to be much harder, even with immigration, to have a young and a vibrant population".

Singapore is also wrestling with the issue of a fast-ageing population. Those aged 65 and older formed 13.1 per cent of the citizen population as of June, up from 12.4 per cent in the same period last year.

There are now only 4.9 citizens in the working age band of 20 to 64 for every one aged 65 and above.

Foreigners have boosted the workforce, but the Government has said that there are limits to this growth.

Economist Song Seng Wun said that if population growth continues to plod along at its current pace of about 1.2 per cent, it will take about 14 to 15 years to increase the population by one million.

At that rate, the population will hit seven million by 2035.

The Population White Paper indicated a 6.9 million population figure in 2030 as a projection for the purpose of land use and infrastructure planning.

So if population growth continues at the current pace, the Government will have time to plan ahead and ensure that infrastructure is in place to accommodate the population, Mr Song said.