Temporal stability in the distribution of behavioral states for individual human fetuses.
Although behavioral state analyses have been useful in differentiating between groups of normal and at-risk fetuses, the large between-subject differences in the percent time spent in the various behavioral states poses a major obstacle in identifying abnormal neurological functioning in individual fetuses. Does this variability represent a true difference in state organization between fetuses, or does it simply reflect individual fluctuations in state control at the time of observation? To answer this question, we examined each of 33 human fetuses for 4 h on three separate days between 38 and 40 weeks gestation. The percent time spent in each behavioral state and in transition and insertion periods was determined for each of the three 4-h study sessions, and within-subject analysis of variance was performed to obtain an objective measure of state profile consistency for each fetus. We found that, on the average, fetuses exhibited remarkable within-subject consistency in their state profiles. However, even among this group of low-risk fetuses, there were significant differences in the degree of state organization achieved by individual fetuses. These findings, which indicate the existence of a well-developed central nervous system before birth, suggest that individual differences in the consistency of behavioral state profiles may be indexing important between-subject differences in neurological development.
Groome
L J
LJ
Department of Obstetrics and Gynecology, University of South Alabama, Mobile 36617, USA.
Singh
K P
KP
Bentz
L S
LS
Holland
S B
SB
Atterbury
J L
JL
Swiber
M J
MJ
Trimm
R F
RF
D001519:Behavior / Q000502:physiology*; D005260:Female; D005333:Fetus / Q000502:physiology*; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D013997:Time Factors