As expected, China's growth slowed to 6.1 per cent previous year, from 6.6pc in 2018, data from the National Bureau of Statistics showed.
US-based academic Yi Fuxian, senior scientist at the University of Wisconsin-Madison, told the AFP news agency that even though China has abolished its One Child Policy, there has been a shift in the mindset of the population, with people now used to smaller families.
But most of the United States tariffs on Chinese imports remain in place.
China's National Bureau of Statistics says the economy expanded 6.1 percent in 2019.
Australian shares reached fresh all-time highs for a fourth consecutive day following the signing of a trade deal between the USA and China earlier this week.
Chinese mothers gave birth to 14.65 million children a year ago, a birth rate of 10.48 babies per 1,000 people, according to figures from the National Bureau of Statistics.
Despite a "phase-one" deal reached between Beijing and Washington on Wednesday, which will see the US lower tariffs on $120 billion of Chinese goods in return for Beijing buying $40 billion worth of American farm goods, economists remained downbeat on China's growth outlook this year.
Policy makers have signaled they are prioritizing economic stability in 2020, with stimulus to be kept basically unchanged. "The trade deal provided some short-term support for the economy, but there still exists great uncertainty in the long run".
In 2019, there were 10.48 births per 1,000 people, the lowest birth rate since 1949, the year the PRC was founded. The number of newborns in 2019 fell to 14.65 million, a decrease of 580,000 from the year before.
China's migrant worker population grew 0.8 percent to top 290.8 million, while their average monthly income rose 6.5 percent to 3,962 yuan (about $582), NBS data showed. Still, China's GDP growth past year was the slowest since 1990, according to Reuters records.
The one-child policy was introduced in the year 1979 to control the country's population boom.
"Retail sales growth were steady, indicating still pretty resilient consumers despite growing downward pressure on the labor market", she said.
Experts say that improved education and higher incomes in China have led to delayed marriage and childbirth, and that once-strict government restrictions on births have made one-child households the norm.