Assessment of fetal lung maturity by a microviscosimeter

A new method of rapid antenatal assessment of fetal lung maturity was evaluated in relation to the newborn outcome and two other accepted test. This method is based on fluorescence depolarization (FD) technique. The special instrumentation required for this method (the Microviscosimeter) was found to be simple and easy to handle even to nonprofessional personnel. Analysis of 47 samples of amniotic fluid received within 48 hours of delivery demonstrated that lung maturity threshold may be related to a numeric value (P value) measured by this technique. With a P value of less than 0.320 respiratory distress syndrome (RDS) is unlikely to develop. With a P value greater than 0.340, chances for RDS, usually severe, are high. With a P value of less than 0.340 but greater than 0.320, RDS may or may not develop. This method did not prove to be more reliable then the determination of L/S ratio by thin layer chromatography, but its advantage is that it supplies the results in less then an hour. The FD technique proved to be more reliable then the commonly used foam stability test.