Abstract
The data that Shapiro and Moriyama have collected from 11 countries is analzed. In 1950-1960, as in former decades, factors that have a bearing on mortality of the 1st post-natal week differ from those that dominate death rates of the 2nd - 4th week while factors which have an impact on the latter also dominate mortality of the rest of the 1st year. Mortality by the status of legitimacy and the interrelations between maternal and perinatal mortality are discussed.