title: Sex differences in high-risk premature infants' asymmetric movement development.
abstract: 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.
authors.affiliation: University of Illinois Chicago, College of Nursing, Chicago, IL, USA.
authors.forename: Mary Pope
authors.initials: MP
authors.lastname: Grattan
authors.forename: Michael N
authors.initials: MN
authors.lastname: Nelson
authors.forename: Rosemary C
authors.initials: RC
authors.lastname: White-Traut
authors.forename: Ushanalini
authors.initials: U
authors.lastname: Vasan
authors.forename: Guo-Guang
authors.initials: GG
authors.lastname: Gu
authors.forename: Susan
authors.initials: S
authors.lastname: Littau
mesh_terms: 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