Dangers Await BabiesWith Altitude

Women who live inthe world's highest communities tend to give birth to underweight babies,a new

study suggests.Thesebabies may grow into adults with a high risk of heart disease and strokes.

Research has hintedthat newborns in mountain communities are lighter than average.But it wasn't

clear whether thisis due to reduced oxygen levels at high altitude or because their mothers are

under-nourished一many people who live at high altitudesare relatively poor compared with those living lower

down.

To find outmore,Dino Giussani and his team at Cambridge University studied therecords of 400 births

in Bolivia during 1997 and 1998.The babies wereborn in both rich and poor areas of two cities:La Paz and

Santa Cruz.La Paz isthe highest city in the world,at 3.65 kilometers above sea level,while Santa Cruz is

much lower,at 0.44kilometers.

Sure enough,Giussanifound that the average birthweight of babies in La Paz was significantly lower than

in Santa Cruz.Thiswas true in both high and low-income families.Even babies born to poor familiesin

Santa Cruz wereheavier on average than babies born to wealthy families in lofty La Paz."We were very

surprised by thisresult,"says Giussani.

The results suggestthat babies born at high altitude are deprived of oxygen beforebirth."This may

trigger the releaseor suppression of hormones that regulate growth of the unborn child," saysGiussani.

His team also foundthat high-altitude babies tended to have relatively larger heads compared withtheir

bodies.This isprobably because a fetus starved of oxygen will send oxygenated blood to thebrain in

preference to therest of the body.

Giussani wants tofind out if such babies have a higher risk of disease in later life. Peopleborn in La

Paz might be proneto heart trouble in adulthood,for example.Low birth weight is a risk factor forcoronary

heart disease.Andnewborns with a high ratio of head size to body weight are often predisposed tohigh blood

pressure and strokesin later life.Giussani did notexpect to find that the weight of a baby had little to do with the financialconditions of the family he was born into.

A.Right

B.Wrong

C.Not mentioned