Combining activity and grimace scores reflects perinatal stability in infants <32 weeks gestational age

Over 95% of infants less than 32 weeks gestational age-very preterm infants (VPTI)-require cardiorespiratory support at birth. Clinical condition at birth is assessed by the Apgar score, but the precision and accuracy of activity and grimace has not been evaluated. We hypothesised activity and grimace could predict the level of cardiorespiratory support required for stabilisation.

Two hundred twenty-nine videos of VPTI resuscitations at Monash Children's Hospital and The Royal Women's Hospital, Melbourne were evaluated, with 78 videos eligible for assessment. Activity and grimace were scored (0, 1, or 2) by seven consultant neonatologists, with inter-rater reliability assessed. Activity and grimace were correlated with the maximum level of cardiorespiratory support required for stabilisation.

Kendall's Coefficient of Concordance (W) showed strong interobserver agreement for activity (W = 0.644, p < 0.001) and grimace (W = 0.722, p < 0.001). Neither activity nor grimace independently predicted the level of cardiorespiratory support required. Combining activity and grimace showed non-vigorous infants (combined score <2) received more cardiorespiratory support than vigorous (combined score ≥ 2).

Scoring of activity and grimace was consistent between clinicians. Independently, activity and grimace did not correlate with perinatal stabilisation. Combined scoring showed non-vigorous infants had greater resuscitation requirements.

Our study evaluates the precision and accuracy of activity and grimace to predict perinatal stability, which has not been validated in infants <32 weeks gestational age. We found strong score agreement between assessors, indicating video review is a practical and precise method for grading of activity and grimace. Combined scoring to allow a dichotomous evaluation of infants as non-vigorous or vigorous showed the former group required greater cardiorespiratory support at birth.