The expression of pain in infants with developmental delays

To explore how infants with developmental delays express pain, we analysed facial expressions of infants receiving their routine immunization at around 4-6 months developmental age. The sample included eight infants with developmental disabilities (mean developmental age 4.8 months) and 30 typically developing infants (mean age 4 months). The Maximally Discriminative Facial Movement Coding system was used to code infant facial expressions during immunization.

The pain expression was by far the most common of all facial expressions following immunization for both groups of infants. Those with disabilities produced significantly fewer discrete high-intensity expressions of pain, and significantly more blended expressions than typically developing infants. Expressions of fear, sadness and anger were relatively infrequent in both groups. Infants with disabilities used their upper face less often than typically developing infants, and their mid face was uncodeable more often.

Infants with developmental delays were likely to show pain in facial expressions less clearly than typically developing infants. It is important for health care professionals to be aware that this may be the case when considering the administration of analgesia for such children.