A report by Health Ministry shows that average number of children a woman bears in her lifetime is down to 1.25 in 2005 as opposed to 1.2888 in 2004.

According to a report by Reuters, demographers say a rate of 2.1 is needed to sustain world's second-biggest economy from an aging, shrinking population.

Japan's slumping birth rate has been attributed to long working hours for both men and women, the high cost of putting children through a highly competitive school system, and barriers to women advancing in the workplace while raising kids.

The latest drop in the fertility rate will likely put pressure on the government to review its social welfare policies including pensions and medical care, since officials had assumed the fertility rate would bottom out at 1.31 and then recover, Kyodo news agency said.