ACUTE EFFECT OF MATERNAL SMOKING ON RESISTANCE INDEXES IN THE FETAL UMBILICAL ARTERY AND MIDDLE CEREBRAL-ARTERY

23 healthy smokers with uneventful singleton pregnancies underwent Doppler-flow measurements of the foetal umbilical artery and middle cerebral artery before and ten minutes after smoking one cigarette. In both arteries the resistance indices (RI) did not change significantly. Maternal mean arterial blood pressure and heart rate increased significantly after the smoking of the cigarette. Neither the group with an RI increase of greater-than-or-equal-to 5 % in the foetal umbilical artery (n = 7) nor the group with an increase of the RI in the foetal umbilical artery and, at the same time, a decrease of the RI in the arteria cerebri media (n = 5), showed a significant difference concerning maternal haemodynamic parameters and the number of cigarettes smoked before and during pregnancy. The results suggest, that the smoking of one cigarette in uneventful pregnancy does not produce acute haemodynamic effects in the foetus.