Key points are not available for this paper at this time.
The data used in this study are based on the information reported on the 840,000 birth records for infants born during January, February, and March, 1950, throughout the country,* and on the death certificates for the members of the group who died within four weeks after birth. To consolidate the statistics appearing on both sets of forms, death records were matched against birth records.
Sam Shapiro (Wed,) studied this question.