The intramuscular application of tramadol in birth-giving mothers almost freely reaches the neonate, confirming a high degree of placental permeability. The neonates already possess the complete hepatic capacity for the metabolism of tramadol into its active metabolite. However, the renal elimination of the active tramadol metabolite M1 is delayed, in line with the slow maturation process of renal function in neonates. Despite this difference in pharmacokinetics between neonates and adults, the intramuscular application of tramadol at the recommended dosage range during delivery appears to effective in the relief of labour pain.