Acute effect of maternal smoking on the maternal and fetal cardiovascular system.

Maternal and fetal cardiovascular dynamics were studied in relation to maternal smoking in 18 healthy nulliparous subjects randomly divided into a smoking (n = 9) and a control group (n = 9) between 34 and 38 weeks of gestation. At the end of the study, data from 7 smokers and 7 controls were available for analysis. A significant rise in maternal heart rate and systolic blood pressure was observed during and following smoking one cigarette. A significant increase in fetal heart rate occurred following smoking, whereas mean blood flow velocity and vessel diameter in the fetal descending aorta as measured by pulsed Doppler and time motion techniques did not demonstrate any significant changes.