[Fetal pulmonary artery blood flow depending on fetal lung maturity]

The ultrasonographic assessment of fetal lung maturity by evaluating the elasticity of lung tissue, Dynamic Lung Score (DLS) has been being performed since 1986 in ObGyn Department in Tychy (Medical University of Silesia). The lung elasticity is evaluated on the cross sections of fetal thorax, on the level of heart ventricles. The result of the evaluation is given as the three degree scale, in which I degree indicates the lack of elasticity and fetal lung immaturity, II degrees indicates partially expressed elasticity, corresponding with incomplete maturity of lung tissue, and III degrees represents full elasticity and indicates complete maturity of fetal lungs. This study was designed to compare fetal pulmonary artery blood flow with the maturity of fetal lung tissue evaluated during the ultrasonographic assessment of fetal lung tissue elasticity. The examination was performed on pregnant women, beginning on 27th week gestation. During the examination the mean Pulsatility Index was decreased, particularly in fetuses with II degrees lung maturity. The Resistance Index (RI) was found to be stable and independent of gestational age. In the group with I degree lung maturity (DLS I), the mean PI = 2.643 (+/- 0.229), mean RI = 0.879 (+/- 0.036), in DLS II group PI = 2.039 (+/- 0.262), RI = 0.868 (+/- 0.037), and in DLS III group PI = 2,500 (+/- 0.100), RI = 0.900 (+/- 0.100). Comparing the ultrasonographic evaluation of fetal lung maturity with fetal pulmonary artery blood flow allows more accurate assessment of fetal lung maturity. Fetal lung maturity can not be evaluated univocally on the basis of blood flow assessment. Because of the divergence of blood flow parameters further studies including bigger population seem to be necessary for verification of the results and for establishing the reference values.