Maternal alcohol consumption during pregnancy may delay the development of spontaneous fetal startle behaviour.

Maternal alcohol consumption during pregnancy may delay the development of spontaneous fetal startle behaviour. Previous study indicated that fetuses exposed to alcohol exhibited a significantly higher incidence of spontaneous startles compared to fetuses not exposed at 20 weeks gestation. This study examined startle behaviour longitudinally from 20 to 35 weeks gestation to determine whether the previous results were due to 'developmental delay' or a 'permanent effect'. The number of spontaneous startles exhibited by fetuses of mothers who drank during pregnancy and fetuses whose mothers did not drink was recorded at 20, 25, 30 and 35 weeks gestation during a 45-min observation. The results indicate that exposure to alcohol during pregnancy significantly increases the exhibition of spontaneous startles by the fetus but across gestation there is significant catch-up in startle behaviour. The results suggest exposure to alcohol delays the natural maturation of spontaneous startle behaviour of the fetus but also has a smaller 'permanent' effect. It is suggested that these effects are mediated by alcohol exerting an effect on the inhibitory pathways controlling startle behaviour.