Contribution of genetic disorders to neonatal mortality in a regional intensive care setting.

We examined the contribution of chromosomal abnormalities, mendelian disorders, and birth defects to mortality in a regional neonatal intensive care unit by medical record review of neonatal deaths in that unit. Of a total of 296 infant deaths during the 5-year period June 1986 to May 1991, 69 (23.3%) had a genetic disorder. By diagnostic category, 18.8% had a chromosomal abnormality, 10.1% had a mendelian condition, 42% had a single primary defect in development, and 29% had an unrecognized pattern of malformation. The rate of autopsy and genetic evaluation differed markedly between these diagnostic categories. A comparison was made of underlying cause of death determined from medical records with underlying cause as classified by vital statistics nosologic procedures. No death certificate was on file for two of the deaths; for the remaining 67, 27 (40.3%) had an erroneous or misleading underlying cause of death as determined from vital statistics. The important contribution of genetic disorders to neonatal mortality in this high-risk population and the relative underrecognition of these disorders by vital statistics sources indicate that efforts aimed at reducing neonatal mortality will require a full range of preventive health activities, including preconception, prenatal and perinatal assessment, and counseling. Improved data collection techniques need to be developed to understand the contribution of this group of conditions to total neonatal mortality.