London - Conventional wisdom has long held that pregnant women develop an uncontrollable urge to keep things tidy.

And, according to scientists, that wisdom is correct. They say that getting the home in good order shows that an expectant mother’s evolutionary instincts to ‘nest’ are kicking in.

The mothers-to-be they surveyed found themselves doing DIY, de-cluttering and keeping the fathers close to home.

But one part of the stereotype is wrong, they found – while they want to prepare their home for the baby, mothers-to-be do not clean obsessively.

The Canadian researchers said the pregnant women seemed overwhelmed by a deep-seated biological need to prepare for their baby – and protect it.

The psychologists, from McMaster University in Ontario, based their findings on a survey of more than 300 women, around half of whom were pregnant. The experiments showed nesting behaviour was more common in the mothers-to-be.

It increased through pregnancy, but fell away post-partum, or after the birth.

Writing in the journal Evolution and Human Behavior, they said: “Nesting is not a frivolous activity. It ties us to our ancestral past.

“Human infants are extremely vulnerable and infant care is all-consuming during the early post-partum period.

“A safe environment must be built during pregnancy; there is no time during the early post-partum period.”

Despite the stereotype, mothers-to-be were far from obsessed with hygiene, and prioritised being organised over cleaning. Researcher

Dr Mel Rutherford said this suggests that the women were driven by their biology, rather than by people’s expectations.

British pregnancy expert and mother-of-two Linda Geddes said she was not surprised by the findings, but added: “Personally, I completely dismantled a double-buggy, put it in the bath and scrubbed it until it was spotless in the run-up to our son’s birth last year.” - Daily Mail