The research carried out by price comparison website Money Supermarket revealed a third of expectant mothers are planning to return to work after between six and eight months at home with their new baby, while one in 10 of the 315 pregnant women surveyed, said they would cut short their leave after as little as three to six months.
A further one in 10 said the squeeze on their finances amid high living costs and stagnant wages means they will only be able to take between three and six months off.
The research found 44% of parents who said they are worried how they will manage financially when their family expands said that the stress has caused them to row with their partner.
Clare Francis from MoneySupermarket said: "Having to adjust your lifestyle to cope with the new arrival is hard enough, but with many couples seeing a fall in income due to one of them giving up work or taking maternity leave can heap further pressure on families when they least need it."
The Government confirmed plans in last week's Budget for a tax-free childcare scheme worth £1,200 a child for working parents from 2015.
Minimum statutory maternity pay (SMP) rules mean that mothers receive 90% of their average weekly earnings for the first six weeks of maternity leave, followed by further payments, which vary according to a mother's usual earnings, for the next 33 weeks.
Justine Roberts, CEO and co-founder of website Mumsnet, said: "There are all kinds of financial pressures on parents, whether it's the dip in salary while on maternity leave or the rising cost of childcare.
"It's great to budget if you can, but a helpful piece of advice from Mumsnet users is to hold fire on buying a multitude of baby products in advance, and to wait until the baby arrives before making big purchase decisions."
