Phosphatidylglycerol determination in the amniotic fluid from a PAD placed over the vulva: a method for diagnosis of fetal lung maturity in cases of premature ruptured membranes.

Four hundred and forty seven pregnant women with ruptured membranes, were prospectively studied in order to assess the diagnostic capacity of Phosphatidylglycerol (PhG) determination in amniotic fluid recovered from vulval pads in the diagnosis of Hyaline Membrane Disease (HMD). The identification of PhG was performed using one dimensional silica gel thin layer chromatography. The sensitivity of PhG determination in the diagnosis of HMD in newborns of the total population was found to be 88.2%, with a specificity of 76.9%. In the study population, the incidence of HMD was 7.6%, the negative predictive value was 98.8% and, the positive predictive value was 24.0%. When the 265 newborns of the gestational age group of less than or equal to 34 weeks is considered, we observed an incidence of HMD of 12.1%. The diagnostic capacity of PhG in this group was shown by a sensitivity of 87.5%, a specificity of 76.4%, a positive predictive value of 33.7% and a negative predictive value of 97.8%. This method of assessment of fetal lung maturity has a diagnostic capability similar to that described by other authors, who used amniotic fluid obtained vaginally or transabdominally. The procedure described here of amniotic fluid collection is non-invasive, harmless to the mother and fetus and simple to perform. The characteristics of this method, allow serial studies of the amniotic fluid to be carried out.