Anita Holdcroft, the anaesthetist leading the team, based at the Royal
Postgraduate Medical School in London, believes that this unexpected observation
could be linked to the cognitive problems experienced by some pregnant women and
new mothers. “These are very early findings, but it may be that the two features
are linked,” she says.

At a meeting in Sheffield this week, organised by the Physiological Society,
Holdcroft described how the researchers built up three sets of magnetic
resonance images to give three-dimensional pictures of the brains of 10 healthy
women. The first set were taken towards the end of pregnancy, the second 6 to 8
weeks after delivery and the third up to 6 months later. Comparing the images,
Holdcroft and her colleagues found that as the women’s physiology returned to
the non-pregnant state, their brains increased in size. It is possible that the
women’s brains were swelling from a normal size, the researchers concede, but
they think it much more likely that the women’s brains had shrunk during
pregnancy.

The pituitary gland at the base of the brain—which releases a
wide range of hormones, including some responsible for regulating
reproduction—showed the opposite effect, apparently increasing in size
during pregnancy.

Holdcroft believes that the changes in the brain are more likely to be the
result of changes in the volume of individual cells, rather than changes in the
number of cells in the brain. Her team is now investigating the mechanisms
involved.

The research into brain size and pregnancy started with women who developed
pre-eclampsia, a syndrome involving high blood pressure and fluid build-up that
affects some pregnant women, causing their faces, legs and arms to swell. If
untreated, it can lead to fatal seizures.

“We assumed that their brains would also swell, but last year we found that
they shrink,” says Holdcroft. The new research suggests that this is not a
symptom of pre-eclampsia, but a normal feature of pregnancy.

The quest to understand our origins has fuelled many a life’s work.
Philosophers and theologians have pursued a myriad of questions that begin
with ‘who’ and ‘why’. In A Time To Be Born, Peter Nathanielsz takes us through
much of what has been learnt by scientists asking the questions that open
with ‘what’ and ‘how’.

The book is packed with information leading any diligent reader to some
of research’s sharpest cutting edges. It pours light on both the complexity
and elegance of fetal development that occurs largely unseen and, more often
than not, without flaw.

Nathanielsz highlights how far we still have to go before answering
some of the most basic of questions. It may surprise you to learn that we
do not know what triggered your birth; what is it that signals a fetus to
say ‘OK, here I come’. It may also surprise you to learn that from what
we know so far, it is the fetus, not the mother who makes the decision –
not a new idea by any means since it was first mooted two thousand years
ago by Hippocrates.

Not only is the fetus in charge of the decision to come out, it is
also responsible for its life inside. As many a mother will tell you, it
has a daily routine of exercise and rest, and will experience its own version
of jet lag as mother travels from one time zone to another.

At times, Nathanielsz appears to suffer from his own enthusiasm. Rather
than giving a clear presentation or debate, he introduces too many ideas
at once, somewhat like a person so desperate to tell you what they’ve just
discovered that they start every-where at the same time. This tendency creates
repetition throughout the book.

He hopes his writing will influence decision makers in society, but
refuses to be drawn on some of the deeper issues that the book inevitably
raises. For example, having shown just how capable an individual the fetus
is, he then refuses to pass comment on when personality may develop. Such
issues, he claims, are ‘beyond the scope of this book, and are questions
for ethicists, theologians and philosophers. ĐÓ°ÉÔ­´´s can only provide
the information on which to base our judgements.’

Surely scientists must participate in these debates. Then we can help
people who ‘flounder in the face of decisions as when to turn off life-support
for babies’ or ‘grope for answers to the ethics of termination of unwanted
ąč°ůąđ˛ľ˛Ô˛š˛ÔłŚžąąđ˛ő’

Pete Moore is a fetal physiologist and write.