Four out of 10 women in Penang bow out of the workforce before they hit their mid-40s because they cannot juggle both work and their kids.
They start filing out of the workplace from as young as 30, with three out of 10 quitting for the sake of their children.
Only about half of women in their early 50s are still at work in Penang.
This is in sharp contrast to the statistics for men. Between 93 per cent and 98 per cent of men aged from 25 to 55 are breadwinners, according to research by the Penang Institute.
Research officer Yeong Pey Jung also discovered that women who forego their careers for their children do so regardless of how much they earn.
In her survey on 667 randomly picked women here, she found that the pattern stayed with those earning between RM2,000 (S$720) and RM7,000 a month.
"Women who earn well tend to marry well too. Their husbands' incomes are enough for them so when they become full time mothers, they lose the will to work.
"Those with middling income find that working is pointless if more than half their salaries go to paying day care centres, babysitters or nurseries while they work."
Another 60 women in 10 focus groups in Yeong's study and those who did not have children shared none of those perspectives.
"All of them, including undergraduates, firmly believed that they would never abandon their careers if they had children.
"It seems that as soon as maternal instincts kick in, women tend to have a change of heart."
Yeong said this could lead to a loss of gender diversity in organisations.
"With fewer women contributing at work, we risk falling short on the women's touch. The ideas and efforts of women have a positive effect of creating more inclusive approaches and strategies for any organisation," she added.
She said in developed countries like Singapore and Australia, graphs on women participation in the labour force show a double peak or 'M pattern', with women going back to work in their early 40s.
"But in Penang and also for Malaysia, we only have a single peak coming from women aged 25 to 29. It goes downhill after that."
She said there was also expectation in certain sections of society that to be good mothers, women had to stop working.
"Most of the women interviewed found it difficult to manage both home and work commitments. Some pointed out that their husbands were not so supportive and did not help to bear domestic burdens.
"After becoming stay-at-home mums, they also expressed wishful thoughts of returning to work."
The trouble, she said, was that after the kids had grown up, mothers wanting to go back into employment found that their skills and experience were out of date.
She said re-training programmes for women and flexi-hour schemes were vital to ensure that they could return to the country's labour force after their children had grown up.