Related Experiment Video
Updated: Aug 13, 2026
Quantified Assessment of Infant's Gross Motor Abilities Using a Multisensor Wearable
Published on: May 17, 2024
Sex differences in high-risk premature infants' asymmetric movement development
Mary Pope Grattan1, Michael N Nelson, Rosemary C White-Traut
1University of Illinois Chicago, College of Nursing, Chicago, IL, USA.
Insights
High-risk premature infants show sex-specific differences in developing movement laterality. Females exhibit right-sided biases in upper body reflexes, while males do not, suggesting potential early markers for atypical central nervous system development.
Area of Science:
- Neonatal Neurology
- Developmental Pediatrics
- Neuroscience
Background:
- High-risk premature infants often display atypical development in reflexes and postural reactions.
- Understanding early motor laterality patterns is crucial for identifying potential neurological issues.
Purpose of the Study:
- To investigate sex-specific differences in reflex and postural reaction development in high-risk premature infants.
- To explore the utility of the Modified-Measure of Behavioral Laterality (M-MOBL) for assessing atypical central nervous system (CNS) development.
Main Methods:
- The Modified-Measure of Behavioral Laterality (M-MOBL) neonatal assessment was used.
- 26 high-risk premature infants (23-26 weeks gestational age) were assessed at two time points (33-36.5 weeks and 36.5-40 weeks post-conceptional age).
- Data were analyzed using categorical method (CATMOD) repeated measures analysis of variance (ANOVAs).
Main Results:
- High-risk premature females showed right-sided (R) biases in head turning and upper-body reflexes by 35-37 weeks post-conceptional age (PCA).
- High-risk premature males did not exhibit significant R-sided or left-sided (L) biases in most upper-body movements tested.
- Neither premature males nor females displayed asymmetries in foot and leg reflexes, similar to healthy full-term males, but contrasting with full-term females.
Conclusions:
- Sex-specific differences in motor laterality emerge in high-risk premature infants.
- The M-MOBL shows potential as an early screening tool for identifying infants with atypical CNS development and laterality patterns.
- Further research may refine the M-MOBL for early detection of neurodevelopmental deviations.
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.
