‘Baby Brain’… Does it exist?

So I’m FINALLY on maternity leave… apparently now I am allowed to succumb to ‘baby brain’.

I am usually, most definitely, a left-brain person.*

* (Traditionally)
Left brain: language, logic, critical thinking, numbers, reasoning.
Right brain: emotions, music, colour, images, intuition, creativity.

Pregnancy has messed with that. I now find myself crying at everything (although TV life insurance ads are really very touching these days) and due to some inexplicable intrinsic maternal drive, am knitting a pink beanie for our unborn. Yeah, I’ll let you know how that goes…


Is there such a thing as ‘baby brain’?

Some say it’s a myth and that women use it to gain sympathy and excuse laziness. Usually men. The hater kind. The kind that is so jealous that we can have a productive work life AND make new humans. Yeah, sorry we’re so awesome.


There are definite neurophysiological changes that occur during pregnancy – hormonal changes have been well-studied (and I won’t go into the basic physiology of pregnancy here), and increasingly people are looking at alterations in neurotransmitter gene expression… Here are some of the findings:

  • There are alterations in gene expression during pregnancy that specifically change maternal behaviour (to the more bonding-loving-caring-type mother; not the I’m-gonna-beat-you-with-a-wire-coat-hanger-type mother);
  • Some hormones that are released in greater quantities during pregnancy protect the foetus from harmful effects of maternal stress. These hormones have side-effects including calmer mood, sleepiness, decreased stress. All of which contribute to your zen-pregnancy state;
  • Neurochemical changes occur during pregnancy that support nerve sprouting in areas of the brain that are associated with right-sided function (see above) whilst helping decrease fear and stress. This is supported by a very recent study from Royal Holloway, University of London UK, which found that the brains of pregnant women exhibit increased activity, particularly in the right hemisphere and that these changes help mothers to become neurologically prepared to bond with their babies at birth;
  • Looking specifically at memory, it has been found that verbal recall memory (but not recognition or working memory) diminishes during human pregnancy and that these decrements persist after parturition. These are associated with prenatal glucocorticoids and oestrogen, however it is not known whether these are the CAUSE of such memory changes;
  • Studies are showing that these changes in the maternal brain are substantial and permanent. Yikes.
  • Physical findings to support the above – perhaps the most terrifying paper I read… Pregnant women experience a reduction in brain size (which is maximal at birth, and thankfully reversed by 6 months post-delivery). The reduction in brain size is even greater if you have pre-eclampsia.

So is ‘baby brain’ real? It appears so – and it results from a combination of changes in gene expression, hormonal regulation and expression, neurochemistry, neuronal growth and activity, and even the actual size of the brain.

Speaking of brains, mine has nearly imploded from holding it together long enough to post this blog entry. Me go rest now.


Mann PE. Gene Expression Profiling during Pregnancy in Rat Brain Tissue. Brain Sci. 2014 Mar 4;4(1):125-35. doi: 10.3390/brainsci4010125.
Brunton PJ, Russell JA, Hirst JJ. Allopregnanolone in the brain: protecting pregnancy and birth outcomes. Prog Neurobiol. 2014 Feb;113:106-36. doi: 10.1016/j.pneurobio.2013.08.005. Epub 2013 Sep 4. Review.
Zhou IY, Chan RW, Ho LC, Wu EX. Longitudinal metabolic changes in the hippocampus and thalamus of the maternal brain revealed by proton magnetic resonance spectroscopy. Neurosci Lett. 2013 Oct 11;553:170-5. doi: 10.1016/j.neulet.2013.08.041. Epub 2013 Aug 27.
Kinsley CH, Meyer E, Rafferty KA. Sex steroid hormone determination of the maternal brain: effects beyond reproduction. Mini Rev Med Chem. 2012 Oct;12(11):1063-70. Review.
Kinsley CH, Amory-Meyer E. Why the maternal brain? J Neuroendocrinol. 2011 Nov;23(11):974-83. doi: 10.1111/j.1365-2826.2011.02194.x. Review.
Glynn LM. Giving birth to a new brain: hormone exposures of pregnancy influence human memory. Psychoneuroendocrinology. 2010 Sep;35(8):1148-55. doi: 10.1016/j.psyneuen.2010.01.015. Epub 2010 Mar 21.
Oatridge A, Holdcroft A, Saeed N, Hajnal JV, Puri BK, Fusi L, Bydder GM. Change in brain size during and after pregnancy: study in healthy women and women with preeclampsia. AJNR Am J Neuroradiol. 2002 Jan;23(1):19-26.
University of Royal Holloway London. “Preparing for parenthood: Pregnant women show increased activity in right side of brain.” ScienceDaily. ScienceDaily, 6 May 2014.

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