For older generations, the traditional nuclear family is all about married couples with at least two children living under the same roof.

For many young modern couples, however, two children is just too much.

"I'm done after one," says Nguyen Thu Huong, owner of a beauty salon in Hanoi and mother of a seven-year-old son when asked about her plans to have another child.

"Both of us (she and her husband) work full-time and we found the first years of parenthood quite hard. We sometimes worry our child won't have enough company, but we'd rather spend quality time focusing on one," she says.

Huong is not alone. A lot of young couples no longer put much store in the old saying ‘the more, the merrier'. Instead, parents of one child are likely to describe multiple-children families as ‘crowded', ‘overloaded', or ‘stressful'.

"You may not be aware of it, but having many children means you have to divide your love, time, attention and money among your beloved. I prefer focusing all my resources and parenting potential on just the one child," says Tran Minh Nam , who enjoys being the parent of a single daughter.

For Nam , the best way to raise his ten-year-old child is to give her the best he can. This includes sending her to an international standard school in the city, letting her go to summer camps in the UK every year and creating a fund for her to study abroad.

"I could hardly make ends meet if I had a second child. You may think that an only child always means a lonely child, but taking away privileges from this child is not an idea for me," he says.

Director of the Ministry of Health's General Office for Population Family Planning Duong Quoc Trong has said having just the one child is a growing trend in Vietnam 's big cities.

Figures from the 2009 Census of Population and Housing showed that the fertility rate, or the total number of births per women aged 15-49 years, averaged 1.8 in big cities and was as low as 1.45 in HCM City.

Meanwhile, the figure in rural areas remained relatively high at 2.15.

UNFPA Assistant Representative Tran Thi Van tells the online newspaper that the double income one kid trend which had played out in many developed nations, was now making headway in Vietnam .

Financial burdens and pressures, the result of modern life in big cities, are given as the cause for the move towards having just one child.

"Obviously, bringing up a child the best way possible makes young couples exhausted and hesitant to have more kids," she says.

Trong says his office has spent the last 50 years aiming for a rapid reduction in the nation's fertility rate. However, changes over new lifestyles and family sizes would require a more flexible policy in the future.

"Management of population growth rate is a little like control over monetary policies. You have to tighten and loosen as necessary. Several provinces need to lower their fertility rates, some are just fine, and in big cities it might be necessary to encourage people to give birth in the next five or ten years," he says. /.