Although there is generally assumed to be a relationship between pregnancy and the formation of gallstones, available evidence is confusing and indicates little, if any, statistical support for such an opinion. Many years ago Schroeder1 carefully investigated this problem. In the latter part of the 19th century he analyzed 1,150 autopsy cases and, on the basis of these studies, found that 90% of women with gallstones had had children. His figures, which were published in 1892, have been variously and widely quoted since that time as establishing a relationship between pregnancy and the formation of gallstones, although, curiously enough, Schroeder himself did not seem to be particularly impressed with this idea. During the 60-odd years that have elapsed since this work was reported, numerous studies of living patients with gallstones and of postmortem material have been published, with the majority of investigators favoring the idea that pregnancy is an