Having babies really does change women's brains

In her weekly column, Jo Fox rounds up the news and views that might have flown under your radar.

This week, she asks: could so-called 'baby brain' actually be a helpful affliction? Is it time for women doctors to ask for a pay rise? And, when will Australia give three-parent babies the green light?

The upside of 'baby brain'

I'm definitely not the first woman to think she's lost her mind after having a baby, and thanks to the kind people at Nature Neuroscience, I can now rest assured that not only is this totally normal but, ultimately, helpful.

first-of-its-kind study has demonstrated that the architecture of a pregnant woman's brain changes during pregnancy and that this lasts for at least two years.

Like the brain equivalent of defragging your computer, it appears grey matter shrinks during pregnancy as the neural networks become more specialised in areas involved in processing and responding to social signals.

This neural disk clean-up would then, as an example, allow new mothers to better identify and respond to their infant's needs or react to external threats. The hippocampus, a region of the brain associated with memory, also loses volume.

The study also found that those women with the greatest reductions in grey-matter volume were, on the whole, the most strongly bonded with their babies.

"We certainly don't want to put a message out there along the lines of 'pregnancy makes you lose your brain'," said the study's lead author Elseline Hoekzema, a neuroscientist at Leiden University the Netherlands who is also the pregnant mother of a two-year-old.

"Grey matter volume loss can also represent a beneficial process of maturation or specialisation."

The study used MRI scanning to examine the brains of 25 women who had never had children, both before they became pregnant and again from three weeks to a few months after they gave birth.

The team also scanned groups of first-time fathers, men without children, and women without children at the same intervals. They then used computer-based analyses to measure changes in grey matter volume.

The resulting consistent grey matter volume losses in the mothers, but not the other groups, was so clear that the computer algorithm could tell with 100 per cent accuracy which woman had been pregnant.

Two years later, 11 of the 25 mothers — those who had not become pregnant again — returned for MRI scans. The scans showed that grey matter loss remained — except in the hippocampus, where most volume had been restored (phew).

As the paper's authors write: "Pregnancy involves radical hormone surges and biological adaptations. However, the effects of pregnancy on the human brain are virtually unknown."

Which is kind of amazing given the commonplace jokes about pregnant women's minds.

Women make better doctors, study suggests

Any female doctors out there with a New Year resolution to ask for that pay rise? A new study that shows patients treated by female doctors tend to do better than those treated by males may help your negotiation.

Public health researchers at Harvard University found that elderly patients were 4 per cent less likely to die or 5 per cent less likely to be readmitted to hospital within 30 days if treated by female doctors rather than male.

To put it another way, if male doctors achieved the same outcomes as female doctors, there would be 32,000 fewer annual deaths in the US, which is apparently comparable to the number of annual deaths from car accidents.

While the study did not examine the reasons for this, prior studies have found female doctors are more likely than their male colleagues to spend more time with patients, communicate better, and follow clinical guidelines.

Dr Ashish Jha, a professor of health policy at Harvard T.H. Chan School of Public Health and a lead author of the paper, said he hoped the study would spur constructive conversation.

The wage gap "is particularly unconscionable given the performance of women in terms of providing high quality care," he said.

Of course, there is a gender pay gap in many professions.

Data helpfully released by the Australian Tax Office last month shows that male specialist physicians in general medicine earn an average of $315,114 per annum, whereas female specialist physicians earn on average $207,225

So, a bit of a gap to plug, then.

A green light for three-parent babies

Finally, the Human Fertilisation and Embryology Authority (HFEA), the UK's fertility regulator, has approved a controversial IVF technique that allows three-parent babies for clinical use in the UK.

The technique is to be used to avoid passing on the genetically transferred mitochondrial disease — a severe and life threatening condition that starves major organs of energy.

The process uses the mother's and father's nuclear DNA but replaces the mother's defective mitochondrial DNA with healthy mitochondrial DNA from a donor egg.

It is estimated the donor DNA ends up being about 0.1 per cent of the child's genetic makeup and does not influence the personality or appearance of a child, which remains influenced by the mother's and father's DNA or their environment.

"It is a decision of historic importance," said Sally Cheshire, HFEA chairwoman.

"This is about cautious go ahead, not gung-ho go ahead, and there is a long way to go. I'm sure patients will be really pleased by what we've decided today."

This decision means clinics can now seek a licence to practise the technique in certain circumstances, and follows the first birth last year in Mexico of a three-egg baby, as well as a vote in the UK Parliament the year before to legally allow the process.

The procedure is currently not available in Australia, but the Australian Mitochondrial Disease Foundation has called on the Federal Government to amend existing legislation to allow it.

It is estimated that about 1 in every 200 Australians carry this genetic defect and that around 60 children per year will develop a severe or life-threatening form of mitochondrial disease, with half dying in childhood.

A further 30 Australian children born each week — or 1,540 every year — are at risk of developing a mild to moderately disabling form of mitochondrial disease during their lifetime.