Sex differences in high-risk premature infants' asymmetric movement development.
High-risk premature infants are likely to show altered patterns in the development of reflexes and postural reactions. This study used the Modified-Measure of Behavioral Laterality (M-MOBL) neonatal assessment to explore differences in reflex and postural reactions among 26 male and female high-risk, premature infants born between 23 and 26 weeks gestational age. M-MOBL scores at 33-36.5 weeks were compared to those at 36.5-40 weeks of age, shortly before hospital discharge. The M-MOBL data were analyzed using the categorical method (CATMOD) repeated measures analysis of variance (ANOVAs) to compare the development of asymmetric movement patterns in: (1) non-injured and CNS-injured high-risk, premature infants, (2) control and experimental infants who received multi-sensory stimulation, and (3) males and female infants. Consistent with previously published reports of a right-(R) bias for healthy, full-term infant's movements, we found that high-risk premature females showed R-sided biases by 35-37 weeks post-conceptional age (PCA) for head turning responses and reflexes evoked by upper-body stimulation (i.e., palmar grasp, asymmetric tonic neck reflex (ATNR), incurvation). High-risk premature males however showed no significant difference in strength and coordination between the R-side and the left (L), as measured by the M-MOBL, in most of these upper-body movements tested at 35-37 weeks PCA. Neither premature males nor females showed asymmetries in foot and leg reflexes (placing, plantar grasp, Babinski). Healthy, full-term males did not show asymmetries in these reflexes either. However, full-term females showed an R-bias. With further research, the M-MOBL may become a useful instrument for early identification of infants with atypical CNS development who later exhibit atypical laterality patterns.
Grattan
Mary Pope
MP
University of Illinois Chicago, College of Nursing, Chicago, IL, USA.
Nelson
Michael N
MN
White-Traut
Rosemary C
RC
Vasan
Ushanalini
U
Gu
Guo-Guang
GG
Littau
Susan
S
D005260:Female; D007839:Functional Laterality; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007363:Intensive Care Units, Neonatal; D008297:Male; D009068:Movement; D012018:Reflex; D012306:Risk; D012727:Sex Characteristics