ACUTE EFFECTS OF MATERNAL SMOKING ON THE UTERINE AND UMBILICAL ARTERYBLOOD VELOCITY WAVE-FORMS

Objective: The acute effects of smoking during pregnancy on the uterin e and umbilical blood flow velocity waveform were assessed. Methods: T wenty-two chronic women smokers at a mean gestational age of 194.17 +/ - 58.02 days and 21 women nonsmokers at a mean gestational age of 193. 24 +/- 34.71 days were studied. Systolic-diastolic (S/D) ratio, resist ance index, and pulsatility index of uterine and umbilical arteries we re measured in the control group and before and after smoking a single standard 100-mm filtered cigarette in the study group. Results: There was no significant change in the uterine artery and umbilical artery blood velocity waveform indices that could be attributed to the acute effect of smoking in the study group, but all of the uterine artery in dices and S/D ratio in the umbilical artery were statistically higher in the study group in comparison with the control group both before an d after smoking. Conclusion: Our results suggest that smoking causes a n increase in vascular resistance of the placenta and umbilical cord w hen used chronically.