And doctors and midwives should promote the fact that ‘placenta brain’ is not an inevitable part of pregnancy and new motherhood.
It is a popular belief that pregnancy and motherhood affects a woman’s memory, causing them to become more forgetful and absentminded – commonly referred to as ‘baby brain’. But research published in the February issue of the British Journal of Psychiatry finds no evidence that pregnancy or motherhood affects women’s brain power.
The research team, led by Professor Helen Christensen from The Australian National University, recruited 1,241 women aged 20-24 and tested their cognitive functioning. Four areas of cognition were assessed: cognitive speed, working memory, and immediate and delayed recall.
The women were followed up at four-year intervals in 2003 and 2007, and given the same cognitive tests. Seventy-six women were pregnant at the follow-up assessments, 188 became pregnant between assessments, and 542 remained childless. Women who had multiple pregnancies during the 8 year study period were excluded from the analysis as this would introduce additional factors.
The researchers found no significant differences in cognitive change for those women who were pregnant during the assessments and those who were not. In addition, there were no significant differences between those women who had become mothers and those who had not.
This led them to conclude that neither pregnancy nor motherhood have a detrimental effect on women’s cognitive capacity – a finding that directly contradicts previous studies.
So if ‘baby brain’ doesn’t exist, why do so many women think they experience it? Lead researcher Professor Christensen said: “Part of the problem is that pregnancy manuals tell women they are likely to experience memory and concentration problems – so women and their partners are primed to attribute any memory lapse to the ‘hard to miss’ physical sign of pregnancy.
“Pregnant women may also shift their focus away from work issues to help them prepare for the birth of their new baby, while new mothers selectively attend to their baby. However, this shift in attentional focus is adaptive, and certainly cannot be labelled a ‘cognitive deficit’.”
On the back of their findings, the researchers suggest it’s time for parents and professionals to stop believing in the ‘baby brain’ myth. Writing in the British Journal of Psychiatry, Professor Christensen and her team said: “Not so long ago, pregnancy was ‘confinement’ and motherhood meant the end of career aspirations. Our results challenge the view that mothers are anything other than the intellectual peers of their contemporaries.
“Women and their partners need to be less automatic in their willingness to attribute common memory lapses to a growing or new baby. And obstetricians, family doctors and midwives may need to use the findings from this study to promote the fact that ‘placenta brain’ is not inevitable.”
Previous studies have shown that pregnant women perform worse than non-pregnant women on memory and other cognitive tests. But Professor Christensen and colleagues claim the findings from these studies may be the result of biased sampling.
Professor Christensen said: “Previous studies recruited women volunteers already pregnant. In our study the women were recruited prior to pregnancy, so we had already tested their cognitive function before they became either pregnant or mothers. This is critical as it is the first time that pre-pregnancy cognitive scores were available. We could thus see if pregnancy or motherhood produced any greater change in cognition compared to the controls. Our study used a representative population sample too, rather than a convenience sample.”
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Christensen H, Leach LS and Mackinnon A (2010) Cognition in pregnancy and motherhood: prospective cohort study, British Journal of Psychiatry, 196: 126-132