Assessment of optical density on amniotic fluid in predicting fetal lung maturity.

ABSTRACT

The optical density (OD) of 107 amniotic fluids obtained by the amniocentesis after centrifugation at 450 x g or 2000 x g were measured at wave lengths varying from 500 to 650 nm. The OD was found to be lower at the centrifugation at 2000 x g than that at 450 x g and showed a reverse relationship to the wave lengths. In comparison with the foam test, OD measurements predicted the maturity of the fetal lung with less degree of accuracy and gave a higher false negative prediction was still relatively high. It was there fore concluded that OD measurements can not be used to replace the foam test because of their high degree of false negative prediction.