Which needle size and gauge is appropriate for an IM injection to a neonate?

• A. 19 gauge, 1 1/2" (3.8 cm) needle
• B. 18 gauge, 1" (2.5 cm) needle
• C. 20 gauge, 1" (2.5 cm) needle
• D. 25 gauge, 5/8" (1.6 cm) needle

Answer: (D)

For neonates, intramuscular injections require a small-bore, short needle to reach the muscle with minimal tissue trauma. Their muscles are tiny and the subcutaneous layer is relatively thin, so using a thin needle helps reduce pain and tissue damage, while a short length prevents going too deep and possibly hitting bone or deeper structures. A 25-gauge needle with a length of 5/8 inch is commonly recommended for IM injections in this age group, allowing the medication to be deposited into the muscle when the injection is given at 90 degrees into the vastus lateralis.

The other options use thicker gauges or longer needles, which increase the risk of pain, tissue damage, or incorrect deposition (placing medication into subcutaneous tissue rather than muscle) in neonates.