Acute Effects of Maternal Smoking on Human Fetal Heart Function

Abstract

M-mode echocardiography was used to evaluate fetal heart function following maternal smoking in 21 healthy smoking pregnant women between 24 and 39 weeks of uneventful gestation. Prior to smoking one cigarette (nicotine content 1.7 mg), a fetal M-mode echocardiographic examination was performed and repeated 5 and 10 min after maternal smoking. Maternal heart rate and systolic blood pressure increased 8.7% and 15.0%, respectively, immediately after smoking, while diastolic blood pressure remained unchanged. Fetal heart rate increased 4.3% and left ventricular diastolic and systolic diameters decreased 4.5% and 15.0%, respectively. No changes in right ventricular dimensions, ventricular ejection times, ventricular wall thickness or septal thickness were observed. Fractional shortening, mean velocity of fractional shortening, stroke volume and cardiac output of the left ventricle also remained unchanged subsequent to smoking. Thus, maternal smoking of one cigarette seems to elicit only a transitory acceleration in fetal heart rate without concomitant significant changes in fetal heart function.

Acute effects of maternal cigarette smoking on fetal heart rate and fetal body movements felt by the mother

“…Increased basal FHR, returning to the initial level after an average period of 10 min, was observed in both groups immediately after the cigarette smoking; a similar observation was previously reported by others [10].…”

“…A transient peripheral vasoconstriction within the fetus may probably lead to the decrease of fetal somatic activity. Increased mean FHR levels and reduction of short-term variability are probably related not only to the increased placental resistance but also to other acute hemodynamic changes, such as the decrease in left ventricular systolic and diastolic diameters unassociated to significant modifications in stroke volume or cardiac output observed by SORENSEN and BORLUM [10].…”

“…Several studies on the effects of maternal smoking or nicotine alone upon the fetus have been published [2,4,8,10,12,13]. However, to our knowledge, patterns of the modifications induced on fetal heart rate (FHR) and fetal body movements felt by the mother (FM) have not been completely established.…”

Altered Fetal Cardiac Function in Smoking During Pregnancy

“…Similarly, Barutçu et al reported that acute smoking caused a significant change in both left and right ventricular diastolic function in healthy adults [30]. Sorensen and Borlum reported that acute maternal smoking caused a temporary increase in fetal heart rate, however, no significant change in fetal cardiac functions [31]. ICT, as an indication of systolic dysfunction, and IRT, as an indication of diastolic dysfunction, were found significantly high in this study and thus it may be suggested that both systolic and diastolic left ventricular functions of the fetuses exposed to chronic smoking during pregnancy were affected.…”