Researchers have dubbed the phenomenon the ‘three year itch’.
The study by parenting website Netmums found that couples are now four and a half times more likely to split after three years than he traditional seven.
Experts said that trying to juggle careers and parenting while struggling with changing gender roles is leading to more relationship failures.
They also cited a growing trend for ‘fast forward’ partnerships as couples get together later in life, but spend less time getting to know each other before having children, say news reports.
A noteworthy 21 per cent of couples who split, saw their relationship fall apart after they had been together between two and four years. Disturbingly 12 per cent went separate ways within a year.
On the other hand, only three per cent of couples broke up after seven years.
Having children apparently put the greatest strain on a relationship.
Nearly half (42 per cent) of the 1,500 parents questioned said that having children had driven them apart and only a third said it had brought them closer.
Four in five admitted that their relationship suffered as a result of exhaustion caused by the birth of a new baby or looking after young children.
Many struggle to spend quality time together with 15 per cent ‘never’ going out as a couple after having children and 14 per cent managing only one night out a year together.
Nevertheless, many seem to be having children earlier in relationships.
One in 20 couples confessed that they fell pregnant within three months of meeting and 15 per cent were expecting a baby within a year.
“Relationships are tough at the best of times but having children puts an extra strain on them,” Netmums founder Siobhan Freegard, 44, said.
“Add in lack of time, exhaustion, work and money worries and maybe it’s little surprise couples are splitting up earlier than ever before. Certainly, there is unprecedented pressure on women to be the perfect wife, mother and career woman while men are feeling more and more unsure of their role.
“There seem to be a lot of people having children later in life but earlier in relationships. Whereas women tended to have children in their twenties, now it tends to be in their thirties.”
Freegard insisted that possibly some women hear the biological clock ticking and begin looking for a father rather than a boyfriend.
“After ticking off various life and career achievements first, people may want to find someone and for everything to be instantaneously complete.”
“The problem with ‘fast forward’ relationships is if the foundations are not strong then children can quickly make a relationship very wobbly. The research shows we are then giving up too quickly - maybe because it seems there are more choices than there used to be.
“But often simple tricks which cost nothing, like taking time to really listen to each other, can be the key to keeping love alive and remind you why you first fell in love.”
The study revealed that two thirds of couples believe it is harder to maintain a relationship now compared to a generation ago.
About two in five couples said keeping love alive is more difficult with both parties working, while 22 per cent think that couples are less committed and too quick to split.
Indeed, one in ten claimed that couples take having children ‘too lightly’.
Post delivery, 46 per cent of women say they went off sex and two in five felt less attractive after putting on weight.
More than half blamed money worries and debts for driving a wedge though their relationship and one in 14 admitted starting an affair.