Heading in the Right Direction: Understanding Head Turn Preference in the Preterm Infant

SIGNIFICANCE: Premature infants have a higher risk for a head posture preference. Head turn preference is important to study among premature infants because of the biomechanical effects that it may have on the infant. When the head of an infant is maintained in a position, flatting of the skull begins to form on one side. Once an asymmetrical skull has developed, the flattening of the occiput keeps the head positioned on one side. An asymmetrical skull can lead to permanent craniofacial deformities such as asymmetry of the face and ear position. Infantile postural scoliosis and torticollis are more examples of biomechanical asymmetries that may occur from positioning the head to one side for a prolonged time.

These asymmetries have been associated with motor complications as the child continues to develop. The physical effects of head turn preference may lead to developmental delays and could be an early marker for motor delay, cerebral palsy, lower IQs, behavioral problems, and respiratory problems that premature infants are already at risk for in early childhood. Exploration of the associations with developmental outcomes at age 2 yr with head turn preference as a marker for developmental delay will be vital to improving clinical evaluation and establishing early intervention in the neonatal intensive care unit (NICU).

INNOVATION: To date, no reported studies have prospectively examined head turn preference in the NICU in association with developmental delay in children born prematurely. The cohort used in this study will allow for the examination of medical and environmental factors with head turn preference as well as associating these factors with developmental outcomes at age 2 yr. Previous studies have evaluated head turn preference by assessing the assumption (the initial head position following release from midline) and the maintenance (or longevity of a head turn position). In this study, we use assumption and maintenance of head turn preference as well as assessing for severity of the preference by measuring it in relationship to designated landmarks on the body. Using landmarks on the body—such as midline, the nipple line, and the shoulder—will mark severity, creating a larger data set for researchers to investigate.

APPROACH: Is head turn preference in the preterm infant associated with early NICU medical and environmental factors, and does it have associations with outcome at age 2 yr? Head turn preference in the neonate is observed as strong neck rotation to one side and/or an inability to achieve or maintain the head in midline position. Severe head turn preferences may lead to postural asymmetries—such as infantile postural scoliosis, torticollis, and an asymmetrical skull shape—and can promote asymmetric movements in infancy and impair function. There is a paucity of research investigating the role of the NICU environment on head turn preference in the preterm infant and whether it is a marker for adverse neurodevelopmental outcome.

METHOD: This investigation was a prospective longitudinal cohort study. Seventy-one preterm infants born at 30 wk gestation were enrolled at birth. Factors related to the NICU environment and medical interventions were collected. At term-equivalent age, magnetic resonance imaging (MRI) was conducted, and infants underwent neurobehavioral testing, which was videotaped. Head turn preference was quantified from videotaped evaluations on the basis of the natural position of the head at rest, the strength of the head turn preference, and limitations in range of motion of the neck using a newly developed scale. Infants returned at age 2 yr for developmental testing.

Regression models were used to explore associations between head turn preference and the environment, medical interventions, asymmetric movement patterns, early neurobehavioral outcome, cerebral injury, and adverse developmental outcome.

RESULTS: Seventy-six percent of the cohort demonstrated a head turn preference, with 66.2% of those preferring the right side. Associations between head turn preference and environmental or medical factors in the NICU were not observed. Infants with a head turn preference were more likely to demonstrate an asymmetric Moro response (p = .02) and moderate-to-severe cerebral injury (p = .03) at term-equivalent age as well as motor deficits at age 2 yr (p = .03). The key findings of this study were that (1) head turn preference was common in preterm infants at term-equivalent age, (2) a head turn preference by term-equivalent age related to the presence of cerebral injury, and (3) head turn preference was a marker for adverse outcome.

CONCLUSION: Head turn preference is common in preterm infants who are at high risk of developmental impairment. Proper positioning and therapeutic interventions in the NICU can potentially reduce the effects of head turn preference. The primary aims of positioning a neonate are to support posture and movement; optimize skeletal development and biomechanical alignment; provide controlled exposure to varied proprioceptive, tactile, and visual stimuli; and promote a calm, regulated behavioral state. Current neonatal positioning practices include positioning the head in midline and changing the direction of the head of the bed to prevent environmental contributions to preference. Studies have demonstrated less asymmetry among infants positioned in the NICU with an alternative positioning device aimed at maintaining the infant in a flexed, midline-oriented position. Therapeutic interventions that can be conducted in the NICU to address head turn preference include neonatal positioning and passive range of motion to facilitate midline orientation of the head and neck. The effects of positioning, environmental factors, and therapeutic interventions on head turn preference and subsequent development have not been previously studied and warrant investigation.

The study was limited by a small sample size and used recorded videos of the NICU Network Neurobehavioral Scale (NNNS) rather than direct assessment of head turn during clinical exam. We used a sample of preterm infants with significant variability in medical course and interventions, and factors that could be contributing to head turn preference may not have been defined and investigated. In addition, this study did not capture the effect of therapeutic interventions received during the NICU stay.

The NICU has a dynamic therapy program with physical and occupational therapists that provide therapeutic recommendations and educate nursing and families on a routine basis. Observation of a head turn preference, severity of the preference, and range of motion of the neck may provide increased insight into the neurodevelopmental integrity of the neonate and serve as a warning sign for the possibility of cerebral injury and altered motor outcome. By identifying head turn preference in the neonate, targeted interventions can be implemented that can optimize developmental outcome. However, the role of interventions to prevent or minimize early head turn preference are not well understood. More research on head turn preference is warranted.