While experts say paternity leave can enhance the father-child bond and a child's development, most workers at small and medium-sized enterprises (SMEs) find it hard to take such leave.
Only an estimated 40 per cent of eligible male employees in SMEs use the one-week paternity leave, said Mr Kurt Wee, president of the Association of Small and Medium Enterprises (Asme).
Member companies face escalating costs and manpower constraints, he told The Straits Times, noting that companies also have to release NSmen for two or three weeks a year for in-camp training.
Assuming three weeks each of annual leave and in-camp training, and deducting public holidays, many male employees work only around 10 months a year, he added.
He said: "It is in SMEs that often members of the workforce are given extra flexibility and time to attend to private, urgent or family matters."
What may be more important now, he said, is ensuring that costs do not rise, which could result in a rise in unemployment.
The extension of compulsory paternity leave from one to two weeks should be considered only after next year, he added.
Legislation was passed in January 2013 so that men with children born after May 1, 2013, could take a week of government-paid paternity leave. This was enhanced in August last year, when employers were encouraged to give an extra week voluntarily to men with babies born after Jan 1 last year.
While the take-up rate for paternity leave is still modest, Social and Family Development Minister Tan Chuan-Jin said in Parliament in January that the number of fathers taking a full week of paternity leave more than doubled between 2013 and January this year.
Experts said paternity leave can result in long-term benefits.
Ms Vicky Ho, head of research and development at charity Focus on the Family, said: "A dad is the best person to affirm a boy's masculinity and teach him how to channel his strength in positive ways.
"A father's presence also gives a daughter the assurance of safety."
An involved father lowers the chances of sons growing up to be violent, and results in daughters having healthier relationships with the opposite gender, she added.
Dr Sanveen Kang-Sadhnani, principal clinical psychologist and centre manager at Thomson Paediatric Centre, said there was insufficient research to determine the ideal length of paternity leave.
But she noted a study in the United States found that fathers who took leave of at least two weeks had higher parenting satisfaction and were more likely to be involved actively in their child's care nine months after birth.This leads to better developmental outcomes for the kids.
Experts recommend that fathers bond through baby massages, music and storytelling.
Some fathers wish for more than a week of paternity leave.
Mr Ben Lim, 36, a financial services provider, works at a firm that does not offer the extra week of paternity leave. But it was supportive of him taking time to be with his family. When his son, Ezra, was born three months ago, he took a week of his own annual leave to add to one week of paternity leave.
Ezra had jaundice and gastro-intestinal problems, and often had to be taken for hospital check-ups, sometimes even staying overnight.
Mr Lim's wife, Diane, 29, said: "That was my first time being almost completely dependent on my husband in the eight years we've been together."
She added: "It was also really precious to witness that budding father-son bond."