A Breastfeeding Relaxation Intervention Promotes Growth in Late Preterm and Early Term Infants: Results from a Randomized Controlled Trial

Breastfeeding involves signaling between mother and offspring through biological (breast milk) and behavioral pathways. This study tested this by examining the effects of a relaxation intervention in an understudied infant population. Breastfeeding mothers of late preterm (34(0/7)-36(6/7) weeks) and early term (37(0/7)-38(6/7) weeks) infants were randomized to the relaxation group (RG, n = 35), where they were asked to listen to a meditation recording while breastfeeding from 3 weeks post-delivery, or the control group (CG, n = 37) where no intervention was given. Primary outcomes-maternal stress and infant weight-were assessed at 2-3 (baseline) and 6-8 weeks post-delivery. Secondary outcomes included infant length, infant behavior, maternal verbal memory, salivary cortisol, and breast milk composition. Infants in the RG had significantly higher change in weight-for-age Z-score compared to those in CG (effect size: 0.4; 95% CI: 0.09, 0.71; p = 0.01), and shorter crying duration [RG: 5.0 min, 0.0-120.0 vs. CG: 30.0 min, 0.0-142.0; p = 0.03]. RG mothers had greater reduction in cortisol (effect size: -0.08 ug/dL, 95% CI -0.15, -0.01; p = 0.03) and better maternal verbal learning score (effect size: 1.1 words, 95% CI 0.04, 2.1; p = 0.04) than CG mothers, but did not differ in stress scores. A simple relaxation intervention during breastfeeding could be beneficial in promoting growth of late preterm and early term infants. Further investigation of other potential biological and behavioral mediators is warranted.

Automated summary

This study found that a simple relaxation intervention during breastfeeding could promote growth of late preterm and early term infants, reduce crying duration of infants, decrease cortisol levels in mothers, and improve maternal verbal learning ability.