The 266 days that determine your future health
By Roger Dobson
The time spent in the womb can influence whether we suffer, years
later, from cancer, obesity or heart disease - and it may even affect
our love life and ability to play football
Want to be thin, enjoy a long and happy life untouched by dementia,
with a low risk of depression, cancer and arthritis, and have lots of
children? The good news is that medical researchers may have found the
secret of such a healthy, successful life. The bad news is that the
blueprint was laid down during the nine months before you were born.

While the genes we inherit provide us with the basic blueprint for
life, and death, most human disease is the result of the interaction
of genetic susceptibility and environmental factors. While most
research has looked at environmental effects after birth, studies at
Southampton University and elsewhere are increasingly showing that the
266 or so days from conception to birth is the time when much of what
will happen during the decades ahead is determined.

As well as longevity, the likelihood of developing heart disease,
cancer, asthma, high blood pressure, osteoporosis, obesity, depression
and schizophrenia can all be influenced by what happens during those
nine months. And there's more: fertility, family size, soccer ability,
navigational skills, personality and even the likely lifetime number
of sexual partners may all have some links to events in utero.

At the heart of the research is the "foetal origins of disease"
hypothesis, which suggests that diseases may originate through foetal
adaptations to under-nutrition, over-nutrition or unbalanced
nutrition, or to other environmental changes. The debate now is not so
much about the validity of the theory, as to how strong its effects
are, and how they can be changed.

"The fundamental controversy now revolves around not whether but to
what degree environmentally induced factors in early life are major
determinants of disease risk," says Mark Hanson, the British Heart
Foundation Professor of Cardiovascular Science at Southampton
University and co-author of a new report on the theory being published
in the science journal Biology of the Neonate. "The implications of
this are profound. If early-life factors are important, it leads to a
fundamental shift in the management of care prior to conception,
during pregnancy, and following birth."

The mechanisms by which this foetal adaptation occurs are still being
investigated but one suggestion is that the foetus has a genetically
determined range of responses and that the one it selects is
determined by the environment in the womb.

The theory, first put forward by researchers at Southampton
University, is that the foetus responds to an adverse environment by
re-setting its growth plans to prepare for a life in a deprived
environment. But if that environment turns out not to be deprived it
is not best equipped to survive. Fearing that life outside the womb is
going to be as deprived as it is inside, the foetus may, for example,
create a level of insulin resistance that allows survival in times of
famine through efficient storage of fat in rare times of plenty. But
in a postnatal world of constant plenty, that set-up would lead to a
greater risk of obesity, diabetes and heart disease. Research shows
that babies conceived during the Dutch famine (1944-1945) were more
prone to heart disease and obesity.

Professor Peter Gluckman, a respected paeditritian at the University
of Auckland says: "If the foetus has predicted its future environment
correctly, then the developmental path chosen will lead to health in
adult life. However, if the foetal prediction is wrong, then as an
adult it will not have settings appropriate to its environment and
disease risk is enhanced. In other words, the risk of disease is
determined by the degree of match between the prenatal anticipated
environment and the actual postnatal environment faced as an adult."

This anticipatory effect could have an effect on disease risk and
longevity. A new study at the Max Planck Institute for Demographic
Research based on 1,487 elderly Germans found that people born in
June, whose first trimester would have been in the winter, were 23 per
cent less likely to reach 105 than those born in December. In the
womb, perhaps they had been preparing for starvation.

The elements of the environment that can affect the developing baby in
this way include the mother's diet, hormonal changes, changes in the
placenta, maternal exposure to disease and the general weight, fitness
and lifestyle of the mother. "We think it is a combination of maternal
diet and maternal body composition and, potentially, lifestyle, which
might include stress and levels of exercise, as well as smoking of
course," says Professor Hanson.