Physiological changes brought about by pain may contribute to the development of morbidity in neonates. Clinical studies have shown reduction in the changes in physiological parameters and pain score measurements following pre-emptive analgesic administration in situations where the neonate is experiencing pain or stress. Nonpharmacological measures (such as holding, swaddling, breastfeeding) and pharmacological measures (such as acetaminophen, sucrose and opioids) have been used for this purpose.
The primary objective of this review was to evaluate the effectiveness of breastfeeding or supplemental breast milk in reducing procedural pain in neonates. The secondary objective was to conduct subgroup analyses based on the type of control intervention, type of painful procedure, gestational age and the amount of supplemental breast milk given.
A literature search was performed using MEDLINE (1966 - Feb 2006), EMBASE (1980 - Feb 2006), CINAHL (1982 - Feb 2006), Cochrane Central Register of Controlled Trials (Issue 4, 2005 of Cochrane Library), abstracts from the annual meetings of the Society for Pediatric Research (1994 - 2006) and major pediatric pain conference proceedings. No language restrictions were applied.
Randomized or quasi-randomized controlled trials of breastfeeding or supplemental breast milk versus no treatment/other measures in neonates were eligible for inclusion in this review. The study must have reported on either physiologic markers of pain or validated pain scores.
The methodological quality of the trials was assessed using the information provided in the studies and by personal communication with the authors. Data on relevant outcomes were extracted and the effect size was estimated and reported as relative risk (RR), risk difference (RD) and weighted mean difference (MD) as appropriate.
Eleven eligible studies were identified. Marked heterogeneity in terms of control intervention and pain assessment measures were noted among the studies. Neonates in the breastfeeding group had statistically significantly less increase in the heart rate, reduced proportion of crying time and reduced duration of crying compared to swaddled group or pacifier group. Neonates in the breastfeeding group had a significant reduction in duration of crying compared to fasting (no intervention) group, but there was no significant difference when compared to glucose group. Premature Infant Pain Profile scores were significantly different between the breastfeeding group when compared to placebo group and the group positioned in mother's arms. However, these scores were not statistically significantly different in the breastfeeding group when compared to the no treatment group and the glucose group. Douleur Aigue Nouveau-ne scores were significantly different in the breastfeeding group when compared to the placebo group and the group positioned in mother's arms, but not when compared to the glucose group. Neonates in the supplemental breast milk group had significantly less increase in the heart rate and Neonatal Facial Coding Score compared to the placebo group. The differences in the duration of crying time and oxygen saturation change between supplemental breast milk group and the placebo group were not statistically significant. Neonates in the supplemental breast milk group had significantly higher increase in the heart rate changes and duration of crying time compared to glucose/sucrose group. No study was identified that has evaluated safety/effectiveness of repeated administration of breastfeeding or supplemental breast milk for pain relief.