Shanghai's legislators and political advisers are pushing for more incentives to better implement China's new universal two-child policy and encourage women to become mothers for a second time.

Ideas put forward by lawmakers at their ongoing annual gathering include imposing taxes on families rather than individuals, financially subsidizing couples who have two children, extending maternity and childcare leave for both parents and providing more nurseries - especially for children under the age of 3.

These proposals are aimed at helping remove some of the major obstacles that prevent couples from planning for a second child.

China's government decided to adopt a universal two-child policy in October in a bid to address the issues posed by the country's rapidly aging population.

The move, which came into effect on Jan 1, is particularly significant for Shanghai where seniors make up nearly 30 percent of the permanent residents - forecast to increase to 35 percent by 2020.

The city's birthrate is also "among the world's lowest" with an average of 0.7 births per resident couple over the past two years, according to Yang Xiong, a political adviser and director of the Institute of Sociology under the Shanghai Academy of Social Sciences.

Statistics from the Shanghai Commission of Health and Family Planning show that less than 5 percent of eligible couples had applied to have a second child in 2015.

A survey conducted by the Shanghai Women's Federation and Fudan University found that most couples opted out of having more children due to the inherent economic burden of raising offspring, concerns over the possible negative effects it would have on the woman's career and the absence of anyone else to help care for the child.

In a bid to relieve the financial pressure felt by couples wishing to have more than one child, Yang introduced the proposal to impose taxes on families instead of individuals.

"Moreover, multi-tier financial subsidies should be offered to couples with children. Those who have two children should be given more help," he said.

Chen Lei, another political adviser and head of the China Welfare Institute Nursery in Shanghai, identified a general lack of nurseries in the city as another reason why many couples opt out of having more children.

"Around 250,000 babies are born in Shanghai each year but there are only 40 or so nurseries with a capacity to care for 6,000 toddlers aged between 18 and 36 months old," she said.

Officials from the Shanghai Commission of Health and Family Planning said they were soliciting opinions about the ideal length for maternity and paternity leaves so that mothers and fathers could share the burden of childcare.