Blame it on the baby.

If you're pregnant and you've been a little forgetful lately, here's why:

A study conducted by Australian scientists has confirmed what many mothers have suspected: Carrying a baby can make you more forgetful.

Research has found that a woman's memory can be impaired for at least a year after giving birth, although the effects are minor and mainly concern unfamiliar or demanding tasks.

"The memory deficits many women experience during and after pregnancy are pretty much like the modest deficits you'd find when comparing healthy 20-year-olds with healthy 60-year-olds," researcher Julie Henry said.

The Australian study analysed the results of 14 different studies from around the world which tested the memory performances of more than 1,000 pregnant women, mothers and non-pregnant women.

It found that pregnant women performed significantly worse on some, but not all aspects of the test.

The hardest tests for the pregnant women were those which involved new or difficult tasks.

"Regular, well-practiced memory tasks - such as remembering phone numbers of friends and family members - are unlikely to be affected," said the Australian Catholic University's Associate Professor Peter Rendell, who conducted the study with Henry.

"It's a different story, though, when you have to remember new phone numbers, people's names or hold in mind several different pieces of information, such as when multi-tasking."

This study was published in the Journal of Clinical and Experimental Neuropsychology.

The full text is available online.