A Cochrane review included 20 studies with a total of 2 071 neonates. 10 studies evaluated breastfeeding and 10 evaluated supplemental breast milk; 16 studies used heel lance and 4 used venepuncture as procedure. Neonates in the breastfeeding group had statistically a significantly lower increase in heart rate, reduced proportion of crying time and reduced duration of first cry and total crying time compared to positioning (swaddled and placed in a crib), holding by mother, placebo, pacifier use, no intervention or oral sucrose group, or both. Premature Infant Pain Profile (PIPP) scores were significantly lower in the breastfeeding group compared to positioning, placebo or oral sucrose group, or both. However, there was no statistically significant difference in PIPP scores when compared to no intervention. Douleur Aigue Nouveau-ne scores (DAN) were significantly lower in the breastfeeding group compared to the placebo group and the group held in mother's arms, but not when compared to the glucose group. Neonatal Infant Pain Scale (NIPS) was significantly lower in the breastfeeding group compared to the no intervention group, but there was no difference when compared to the oral sucrose group. The Neonatal Facial Coding System (NFCS) was significantly lower in the breastfeeding group when compared to oral glucose, pacifier use, holding by mother and no intervention, but no difference was found when compared to formula feeding.
Supplemental breast milk yielded variable results. Neonates in the supplemental breast milk group had a significantly lower increase in heart rate, a reduction in duration of crying and a lower NFCS compared to the placebo group. Neonates in the supplemental breast milk group had a significantly higher increase in heart rate changes when compared to the sucrose group. Sucrose (in any concentration, i.e. 12.5%, 20%, 25%) was found to reduce the duration of cry when compared to breast milk, as did glycine, pacifier use, rocking, or no intervention. Breast milk was found not to be effective in reducing validated and non-validated pain scores such as NIPS, NFCS, and DAN; only being significantly better when compared to placebo (water) or massage.
Another Cochrane reviewAnother Cochrane review assessed oral sucrose for pain relief in neonates. 20 studies with a total of 2 071 neonates were included. When Premature Infant Pain Profile (PIPP) scores were pooled, sucrose groups had significantly lower scores at 30 seconds (weighted mean difference (WMD) -1.70; 95% CI -2.13 to - 1.26; 3 trials, 278 neonates, no heterogeneity) and 60 seconds (WMD -2.14; 95% CI -3.34 to -0.94; 2 trials, n=164, no heterogeneity) post-heel lance (high-quality evidence). There was high-quality evidence for the use of 2 mL 24% sucrose prior to venipuncture and intramuscular injections. There were no differences in adverse effects between sucrose and control groups. Sucrose significantly reduced duration of total crying time (WMD -39 seconds; 95% CI -44 to -34; 2 trials, n=88).
Comment: The quality of evidence is downgraded by inconsistency (heterogeneity in interventions). The effectiveness of breast milk for repeated painful procedures is not established.