Baby girls who are big at birth may be more likely to develop breast cancer before they reach the menopause, but less likely to develop heart disease, research suggests.
Scientists examined more than 5,000 women born in Sweden during 1915-1923, of which 63 had breast cancer before the age of 50.
They found that women who weighed 4kg at birth were 3.5 times more likely to develop premenopausal breast cancer than those women who weighed less than 3kg.
Babies who were long or who had a large head circumference seemed to be most at risk. The researchers also found that among babies of equivalent size. breast cancer was most likely to develop in those who had a shorter period of gestation.
They believe this may indicate that the crucial factor is the rate at which a baby grows in the womb.