The Origin of the National Institute of Child Health and Human Development

Abstract

In the life history of any person, certain dates stand out with clarity. The most precise, of course, is the birth date. The estimated date of confinement is fairly accurate, and our predictions are helped greatly by modern sonography. Somewhat less precise a date is the last menstrual period, because there may be some confusion when spotting occurs in the middle of the menstrual cycle. When conception is considered, dates and events are very imprecise: When exactly was the twinkle in Dad's eye, when was there a special vacation, or when was there an extra-cold night? This date tends to be considerably less reliable.