The assessment of lung maturity in infants of diabetic mothers, by means of L/S ratio determination in tracheo-pharyngeal aspirate.
The respiratory distress syndrome is more common in the newborns of diabetic mothers. The comparatively high rate of incidence of this syndrome depends neither on gestational age nor delivery route. In view of these facts, the evaluation of fetal lung maturation of diabetic mothers seems to be of the utmost importance. The methods usually employed for the determination of fetal lung maturation are of limited value, because occasionally L/S ratio values, which usually indicate fetal lung maturation, may fall to below critical levels. It is, therefore, extremely important to assess lung maturity in the newborn of a diabetic mother at the time of delivery. In 15 pregnancies complicated by diabetes mellitus of all degrees of severity (A-D), according to the classification of P. WHITE, L/S ratio in amniotic fluid prior to delivery was determined. L/S ratio was determined in tracheopharyngeal aspirate, as well, soon after delivery. In all cases the foam stability test was done in the amniotic fluid before delivery and, when there was a sufficient quantity, also in the tracheo-pharyngeal aspirate. According to the foam test and L/S ratio in the amniotic fluid, all fetuses supposedly had normally matured lungs. Nevertheless, according to these two tests in the tracheopharyngeal aspirate, results indicate lack of full lung maturity in four cases. In fact, all these four newborns developed the respiratory distress syndrome. This test appears to be reliable, simple and non-invasive, and is therefore recommended in babies with diabetes of all degrees of severity, and in all gestational ages.