Habituation in fetuses of diabetic mothers

Fetuses of diabetic mothers exhibit maturational delays in their behaviour and disturbances in behavioural and intellectual functioning in childhood. This suggests an effect of maternal diabetes on the central nervous system of the fetus. The habituation technique enables the functioning of the high er central nervous system to be examined. A normal habituation pattern refl ects an intact central nervous system. Previous studies have found abnormal ities in the fetal central nervous system are reflected in habituation perf ormance. This paper examined the habituation ability of fetuses of diabetic mothers and of non-diabetic mothers. The fetuses were tested at 28, 32 and 36 weeks of gestation. After 2 min of fetal inactivity a series of vibroac oustic stimuli were presented to the fetus. This continued until no respons e was observed on five consecutive stimulus presentations. The number of st imulus presentations to habituate at each gestational age was recorded. The results reveal that there was a highly significant main effect of group (F (1,47) = 19.65, P < 0.001). Fetuses of diabetic pregnancies took longer to habituate. There was a significant effect of gestational age (F(2,94)= 44.6 7, P < 0.0001). In both groups the number of trials to habituate decreased with advancing gestation. There was no relationship between random blood gl ucose levels and habituation performance. The results demonstrate that mate rnal diabetes affects higher aspects of central nervous system functioning in the fetus. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.