Ultrasound observations of subtle movements: a pilot study comparing fetuses of smoking and non-smoking mothers

Abstract

Aim: One way to assess fetal health of smokers is to ask mothers to count perceived movements, an unreliable method hiding differences in prenatal development. The aim of this pilot study was to assess subtle fetal movements in ultrasound-scans and establish whether they differ in fetuses of mothers who smoked and non-smoking mothers. Methods: This longitudinal pilot-study recruited twenty mothers (16 non-smoking; 4 smoking) scanned four times from 24-36 weeks gestation (80 ultrasound scans). Two types of fine grained movements were coded offline and analysed using a Poisson log-linear mixed model. Results: Fetuses of smoking mothers showed a significantly higher rate of mouth-movements compared to fetuses of non-smoking mothers (p=0.02), after controlling for maternal stress and depression. As pregnancy progressed, these differences between the smoking and non-smoking groups widened. Differences between the two groups in the rate of fetal facial self-touch, remained constant as pregnancy progressed and was borderline significant (p=0.07). Conclusion: Rates of fetal mouth-movement and facial self-touch differ significantly between smokers and non-smokers. A larger study is needed to confirm these results and to investigate specific effects, including the interaction of maternal stress and smoking. Additionally, the feasibility of this technique for clinical practice should be assessed.