Best Practices in Intramuscular Injections for Neonates and Infants

Evolving evidence has reshaped best practice standards for intramuscular injections in neonates (birth to 28 days of age) and infants (1 to 12 months of age), refining recommendations related to injection site selection, needle selection, injection technique, safety, and pain management. This clinical practice update synthesizes current evidence and guidance to provide nurses and other clinicians with practical, evidence-based strategies for intramuscular injection in these populations. Current guidance supports use of the vastus lateralis muscle in the anterolateral thigh as the preferred injection site in neonates and infants, age- and size-appropriate needle selection, a 90-degree angle, avoidance of routine aspiration, and use of a single sterile needle and syringe for each injection unless needle change is clinically indicated. Evidence also supports multimodal pain management, including breastfeeding or human milk, oral sucrose or glucose, supportive positioning, caregiver involvement, and selected adjunctive strategies when appropriate. Consistent use of evidence-based intramuscular injection practices can reduce procedural risk, enhance safety, minimize pain, and support positive early health care experiences for infants and families. Updating clinical workflows and education to reflect current evidence can also support adherence to recommended immunization and injectable therapy schedules.