Births in China fell last year even though the world's most populous country has relaxed its infamous one-child policy.

The country saw 17.23 million births in 2017, against 17.86 million the previous year.

The fall was caused by the declining population of women of childbearing age and couples having children later in life, statisticians said.

Births in China fell last year even though the world's most populous country has relaxed its infamous one-child policy (stock photo)

The 1.39 billion-strong nation began to phase out its one-child policy in 2015 because of the economic impact of its ageing population and shrinking workforce.

The policy dates from the 1970s and restricted most couples to one child, with violators facing fines and even forced abortions.

Studies have predicted the loosening of the one-child policy would bring only a relatively small increase in population growth.

The country saw 17.23 million births in 2017, against 17.86 million the previous year (stock photo)

Experts have recommended the country increase its retirement age to address an expected labour shortage and declining economic vitality.

The burden of looking after aging parents is one reason not to have a second child, said housewife Zeng Jialin, who was waiting to pick up her 6-year-old son outside a school in downtown Beijing on Friday.

'They helped us look after one child, but we would have to babysit the second one ourselves. Also, there would be so many things to take care of in terms of time management, economic conditions and pressure,' Zeng said.

Wang Jianjun, the father of an 8-year-old boy, said he was undecided about having another child, but time and financial concerns weighed heavily.

The fall was caused by the declining population of women of childbearing age and couples having children later in life, statisticians said (stock photo)

'Helping with schoolwork takes a lot of time. And until the young one is 2, mother won't be able to work which means a big loss of income that we're not prepared for,' Wang said.

While last year marked a decline, an unnamed official from the National Health and Family Planning Commission said in a statement the number of births remained 'at a relatively high level'.

'Socioeconomic factors have more obviously influenced people's willingness to give birth and child-bearing behaviour,' it said, citing financial costs, lack of childcare services and women's career development pressure as three major reasons.

While overall births fell, the proportion of newborns born to parents who already had a first child rose to 51 percent in 2017, five percentage points higher than 2016, commission said.