The effect of maternal scent on stress, pain, and physiological parameters in infants: A systematic review and meta-analysis.

OBJECTIVE

This study aimed to examine the effects of maternal scent on stress, pain, and physiological parameters in preterm and term infants in the neonatal intensive care unit.

METHOD: A systematic review and meta-analysis were conducted using PubMed, Cochrane Library, Scopus, Web of Science, and the YOK National Thesis Center. Searches were performed between April and May 2026.Risk of bias was assessed using the ROBINS-I and RoB 2 tools. Data were synthesized by meta-analysis, and the certainty of evidence was evaluated using the GRADE approach.

RESULTS

Eight studies involving 483 infants (maternal scent: 239; control: 244) were included. Maternal scent significantly reduced pain during and after procedures (z = 4.11, p < 0.001; z = 4.65, p < 0.0001) and stress levels (z = 11.04, p < 0.0001; z = 3.65, p = 0.0003). Heart rate was significantly lower before and after procedures (z = 1.99, p = 0.05; z = 2.60, p = 0.009), and hospital stay was shorter (z = 2.78, p = 0.005). Oxygen saturation during procedures was significantly higher (z = 2.15, p = 0.03), particularly during endotracheal suctioning (z = 5.28, p < 0.0001). Body weight, respiratory rate, body temperature, and crying duration did not differ significantly. The certainty of evidence was evaluated as very low.

CONCLUSION

Maternal scent may reduce pain, stress, heart rate, and length of hospital stay, while improving oxygen saturation in preterm and term infants. However, given the very low certainty of the evidence, further well-designed clinical studies are needed.