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.