The dysmature infant. Associated factors and outcome at 7 years of age.

Dysmaturity, diagnosed according to the Clifford criteria, was studied for the first time in a black population. The infants and matched control subjects were participants in the Collaborative Perinatal Study in Philadelphia from birth to 7 years of age. The incidence of dysmaturity was 25/1,000 live births; more boys than girls were born dysmature, reversing the normal male/female ratio found among black infants in the Collaborative Study as a whole. The condition was more common among post-term infants but did occur in earlier gestational weeks. The overall characteristics of the condition among this black population did not differ from those previously reported among white populations of various races. Surviving infants developed mentally and physically as well as control subjects. No prenatal or environmental characteristics were found that distinguished mothers of dysmature infants from those of nondysmature infants.