Using census data for more than 1 million people in Austria, Denmark and Australia, scientists at the Max Planck Institute for Demographic Research in the northern German town of Rostock found the month of birth was related to life expectancy over the age of 50.

Seasonal differences in what mothers ate during pregnancy, and infections occurring at different times of the year could both have an impact on the health of a new-born baby and could influence its life expectancy in older age.

"A mother giving birth in spring spends the last phase of her pregnancy in winter, when she will eat less vitamins than in summer," said Gabriele Doblhammer, one of a team of scientists who carried out the research.

"When she stops breast-feeding and starts giving her baby normal food, it's in the hot weeks of summer when babies are prone to infections of the digestive system."

Babies born in the autumn weighed more than those born at springtime, she said. In later life, low birth weight was associated with increased blood pressure, cholesterol levels, some forms of obesity and a decrease in lung function.

In Austria, adults born in autumn (October-December) lived about seven months longer than those born in spring (April-June), and in Denmark adults with birthdays in autumn outlived those born in spring by about four months.

In the southern hemisphere, the picture was similar. Adults born in the Australian autumn -- the European spring -- lived about four months longer than those born in the Australian spring.

The study focused on people born at the beginning of the 20th century, using death certificates and census data. Although nutrition at all times of the year has improved since then, the seasonal pattern persists, Doblhammer said.

In a separate study, Doblhammer analyzed the birth weight of about 3,000 twins born in the United States in the 1970s and 1980s and found that those born in spring and summer weighed less than those born in autumn.

(Xinhua News Agency September 7, 2002)