Foetal mouth movements: Effects of nicotine.

Due to variability in foetal behaviour, examining mouth movements alone may not be the most appropriate method for assessing group differences. However, in line with other research, mouth movement frequency declined between 32- and 36 weeks of gestational age. A combination of foetal behavioural assessments is needed to assess the effects of cigarette and e-cigarette exposure on foetal neurobehavioural development.