The effect of Intraamniotic thyroxine administration on fetal lung maturity in man

In this study we set out to examine the effect of thyroxine injection intraamniotically on the acceleration of fetal lung maturity. 183 samples of amniotic fluid from pathological pregnancies were examined at different stages of pregnancy; to determine fetal lung maturity by the evaluation of “P” (a measurement dependent on micioviscosity) previously described. 16 cases between 29-34 weeks received intra-amniotic thyroxine in order to accelerate the development of fetal lung maturity. In all 16 cases there was a significant improvement in the degree of lung maturity. 14 newborns were definitely mature. The desired maturity was not achieved in only two cases. The results of these 16 cases were cotnpared to a control group (untreated) which were chosen because of an identical gestational age and the same types of pathology. There was a statistically significant difference in the pulmonary maturity value ‘P’ after use of thyroxine in comparison to the control groups.In 15 of the 16 treated cases, there was no RDS (Respiratory Distress Syndrome), and this in spite of the fact that they were all born before 34 weeks of pregnancy, and nine of them by Caesarean Section. In view of these results it seems that thyroxine treatment is one of the most efficient methods of preventing RDS in high risk pregnancies in which there is an indication for early induction of labor.