273 THE HUMAN FETUS AND AIR TRAVEL

Abstract

At artificially maintained cabin pressure in modern aircrafts, the arterial Po2 in healthy adults is close to 60 mm Hg. This relative oxygen deficiency has been discussed as a potential risk for the fetus during flight of pregnant women. In addition, there are speculations about the possible effects of acceleration and emotional stress during flight on the maternal and fetal organism. Investigations in human pregnancy have not been carried out under simulated or real flight conditions. We measured maternal respiratory and heart rate, ECG, transcutaneous blood gases, blood pressure and uterine contractions, fetal beat-to-beat heart rate and cabin pressure in 10 healthy pregnant women during 20 European continental flights. Commercially available or specially adapted instruments were used and observations were recorded on Eproms. The instrumentations were battery powered. Data were analyzed according to the various flight phases and related to the initial phase on the runway (take off, climb, maximal height, descent and landing). Maternal heart rate and blood pressure increased. Po2 decreased significantly. Maternal respiration and Pco2 remained unchanged. In the fetuses there was no instance of bradycardia, no decelerations or reduction in baseline heart rate variability. Mean fetal heart rate remained normal during all flight periods. Significant accelerations of fetal heart rate were observed in some cases.