EVIDENCE THAT FETAL LUNG FLUID AND PHOSPHOLIPIDS PASS INTO AMNIOTIC FLUID IN LATE HUMAN PREGNANCY

Abstract

Summary Estimates of fetal maturity by measurement of amniotic fluid phospholipids are based on the belief that there is passage of fetal respiratory tract fluid into the amniotic cavity, but there is little evidence of such a transfer. Analysis of serial samples of newly‐formed amniotic fluid has given new grounds for believing that the fetal lung contributes fluid and surface‐active lecithin to amniotic fluid in late human pregnancy. Sphingomyelin appears to have a different origin.