Twenty-five studies were included: breastfeeding initiation (n=4,116 participants); breastfeeding rates (n=2,532); exclusive breastfeeding rates (n=5,465).
Initiation (seven studies): High-intensity peer counseling interventions were significantly associated with increased rates of initiation of breastfeeding in three of four studies. Three low-intensity interventions showed no significant difference between intervention and control groups.
Duration (13 studies): High-intensity peer counseling interventions were associated with increased rates of initiation of breastfeeding in five out of nine studies; only one out of five low-intensity peer counseling interventions achieved the same.
Exclusive breastfeeding (12 studies): Peer counseling interventions were associated with significant increases in exclusive breastfeeding rates in seven RCTs specifically designed to evaluate the effectiveness of peer counseling. Mixed results were found in studies not specifically designed to evaluate effectiveness of peer counseling.
Health outcomes (five studies): Breastfeeding peer counseling interventions were associated with significant reductions in rates of infant diarrhoea in four of the five studies. Breastfeeding peer counseling intervention, compared to control, was associated with a significantly longer duration of lactation-induced maternal amenorrhea (one study).
Scale-up: Implementation of scaling-up interventions (details reported in paper) were associated with significant improvement in rates of timely initiation of breastfeeding and exclusive breastfeeding. Further results suggested that it was cost-effective to scale-up breastfeeding peer counseling as part of national breastfeeding promotion efforts (it was unclear whether these studies met the review inclusion criteria).