An Epidemiologic Analysis of Dysmaturity

Abstract

Present-day knowledge of the dysmature syndrome has been evaluated epidemiologically and the incidence and mortality rates estimated for the first time. A clinical definition is desirable for such evaluation in order to avoid inclusion of other groups of infants or exclusion of large or premature dysmature infants. The incidence of dysmaturity, both stillborn and liveborn, is approximately 12% of total births. Perinatal mortality in dysmaturity is estimated to be 3 times the rate in normal newborns. An epidemiological model suggests that 4 of every 1,000 individuals reaching the perinatal period will die during that period with the clinical appearance of dysmaturity. This is 1/8 of all perinatal mortality. The environmental placental dysfunction hypothesis explains the high fetal mortality and its frequency distribution but does not adequately explain the increased noenatal mortality.