A small but growing number of couples in Singapore are choosing to have a large brood, possibly heartened by pro-family policies such as the enhanced Baby Bonus payouts, experts have said.

Financial stability and religious beliefs could also have influenced their decisions, they added.

A total of 2,118 babies born last year were the fourth or more child in their families - the most in the past five years, according to the Report on Registration of Births and Deaths 2017 released this month by the Immigration and Checkpoints Authority.

However, registered births last year were also the lowest in seven years - 39,615 compared with 37,967 in 2010.

These statistics are worrying as Singapore's total fertility rate of 1.16 last year is far below the 2.1 rate needed for the population to replace itself.

Different groups of people are behind the trends, said Associate Professor Kang Soon-Hock from the Singapore University of Social Sciences (SUSS).

"Couples who are contemplating having their first child may face more barriers, such as their own career progression and working towards financial stability," added Prof Kang, who heads the Social Science Core at SUSS' School of Humanities and Behavioural Sciences.

"Couples who already have one or more children may have fewer barriers to overcome as they may have achieved a certain level of stability in their careers."

For this group, enhancements to government policies like the Baby Bonus scheme could have served as an enticement.

The scheme's cash gift of at least $8,000 a baby had been extended to the fifth and subsequent child for those born on or after Jan 1, 2015.

Previously, only the first four children qualified for the cash gift.

Sociologist Tan Ern Ser from the National University of Singapore (NUS) said religion can also play a part, in not sanctioning abortion or family planning.

Still, the majority of babies born from 2013 to last year were the first child for couples, the report showed.

Last year, 18,570 babies born were the first child in their families, a slight drop from 2013's figure of 19,292 babies.

Moreover, women have continued having children when they are older, with the median age of mothers who gave birth to their first child hovering around 30 years old last year.

On the reasons for smaller families in general, Provost-Chair Professor in the Department of Sociology at NUS' Faculty of Arts and Social Sciences Jean Yeung thinks that couples nowadays invest more in a child rather than having many children.

In addition, with a growing number of women becoming more educated and working, marrying and having children are no longer the only ways to achieve social status and economic security, added Prof Yeung. - FELICIA CHOO