A special technique, fluorescent polarization (F.P.) has been used to measure the microviscosity of amniotic fluid. A total of 151 samples of amniotic fluid from 118 patients, both normal and high-risk, were included in this study. The results were compared to L S ratios and to the neonatal outcomes. The F.P. value was found to decrease as pregnancy progressed, and a value of 0.345 or less was found to be associated with apparent fetal lung maturity. The correlation between the F.P. value and the L S ratio was good when mature results were compared ( L S>2 and F.P.≤0.345). When the L S ratio was immature (<2), only 18 out of 82 samples showed an immature F.P. value. There were 99 patients delivered within 5 days of the amniotic fluid sampling and the percentage of correct prediction for RDS was 100 per cent with mature L S or F.P. In cases with an immature L S ratio (<2) the correct prediction of RDS was only 14 per cent; with the F.P. value it was 86 per cent. Six out of seven patients with immature F.P. value (>345) developed RDS and three of these died with hyaline membrane disease. In 83 patients delivered within 48 hours of the amniotic fluid sampling, the predictive value of the F.P. increased to 100 per cent but that of the L S ratio remained 14 per cent.
ASJC Scopus subject areas
- Obstetrics and Gynecology