Utility of a rapid lamellar body count in the assessment of fetal maturity.

The authors investigated the use of a recently described method for the rapid determination of the lamellar body count (LBC) as a means of evaluating fetal pulmonary maturity. Results of the rapid LBC were compared, alone and in combination with the foam stability index (FSI), with the results obtained by thin-layer chromatography (TLC). The study used 90 consecutive amniotic fluid specimens from 82 patients. Rank ordering of the data suggested cutoff points of 19,000/microL for the rapid LBC and 46 for the FSI. Statistical analysis indicated that the addition of the LBC improved the sensitivity of the FSI (P less than 0.01 by the McNemar test), although the reverse was not the case (P greater than 0.1). The linearity and reproducibility of the LBC were considered acceptable.