They have to work more than their brethren elsewhere in the nation and have no time to raise a family, says Nguyen Thien Nhan.

"Reports from local media saying city women are lazy about giving birth are not right, the objective reason is that they work too much. They are too busy to have time to spend with their family and have children," Nhan said at an online conference on Monday.

The city’s current birth rate is 1.33 children per woman, much lower than the national average of 2.1. It has the lowest birth rate of all localities in the country. A similar phenomenon has been observed in several developed Asian countries like South Korea and Japan, which have failed to take the rate beyond 1.3 and are facing a labor crisis.

Nhan, who used to head the country's steering committee on population and family planning, said that a 2017 study had revealed that on average, Vietnamese work 44 hours per week, about five and a half days. People in HCMC, the nation's commercial hub, work 54 hours, or about six and a half days, a week.

He said it was a problem that has to be given serious consideration.

"The city’s labor productivity is three times higher than that of the whole country and workers have to work more than a day over the national average, they do not have time for their families," Nhan said.

He asked the labor union and other relevant agencies to call on businesses to give workers enough time to rest.

City authorities have been considering incentives for couples having a second child as the city’s fertility rate dipped over the last two decades from 1.76 to 1.33 children per woman.

The Department of Population and Family Planning has proposed subsidizing or waiving hospital fees for delivery of the second child and offering families having two children soft loans to buy or rent houses.

Such moves are meant only for official residents of the city and not migrants, the department said in the proposal, which will be submitted to the administration for drafting its population policy for 2021-25.

Other recommendations include extending maternity leave from six months to one year for having the second child and giving the father a month off, and subsidizing kindergarten fees at public facilities for families with two kids.

Population experts have warned the falling birth rate in HCMC could spell disaster for economic growth and welfare systems.

The city has a population of nine million and a population density of 4,363 people per square kilometer, the highest among all Vietnamese localities, according to a 2019 study.

The falling birth rate has resulted in a quickly aging population, which places pressure on the city’s welfare system, including pensions, health insurance and social security, said Pham Chanh Trung, deputy director of the municipal Population and Family Planning Department.

Having a lower working age population, especially young professionals, can also affect the city’s socioeconomic growth, Trung said.

Vietnam's population hit 96.2 million last year, which is third in Southeast Asia and 15th globally, according to the Central General Census and Housing Steering Committee. Males make up 49.8 percent of the population now, a slight increase from last year's 49.4 percent.