共用题干Dangers Await Babies With AltitudeWom

共用题干

Dangers Await Babies With Altitude

Women who live in the world’s highest communities tend to give birth to underweight babies,a new
study suggests.These babies may grow into adults with a high risk of heart disease and strokes.
Research has hinted that newborns in mountain communities are lighter than average.But it wasn’t
clear whether this is due to reduced oxygen levels at high altitude or because their mothers are
under-nourished一many people who live at high altitudes are relatively poor compared with those living lower
down.
To find out more,Dino Giussani and his team at Cambridge University studied the records of 400 births
in Bolivia during 1997 and 1998.The babies were born in both rich and poor areas of two cities:La Paz and
Santa Cruz.La Paz is the highest city in the world,at 3.65 kilometers above sea level,while Santa Cruz is
much lower,at 0.44 kilometers.
Sure enough,Giussani found that the average birthweight of babies in La Paz was significantly lower than
in Santa Cruz.This was true in both high and low-income families.Even babies born to poor families in
Santa Cruz were heavier on average than babies born to wealthy families in lofty La Paz."We were very
surprised by this result,"says Giussani.
The results suggest that babies born at high altitude are deprived of oxygen before birth."This may
trigger the release or suppression of hormones that regulate growth of the unborn child," says Giussani.
His team also found that high-altitude babies tended to have relatively larger heads compared with their
bodies.This is probably because a fetus starved of oxygen will send oxygenated blood to the brain in
preference to the rest of the body.
Giussani wants to find out if such babies have a higher risk of disease in later life. People born in La
Paz might be prone to heart trouble in adulthood,for example.Low birth weight is a risk factor for coronary
heart disease.And newborns with a high ratio of head size to body weight are often predisposed to high blood
pressure and strokes in later life.

Giussani did not expect to find that the weight of a baby had little to do with the financial conditions of the family he was born into. A:Right B:Wrong C:Not mentioned