The care of infants at risk of poor growth and development is a global priority. To inform new WHO guidelines update on prevention and management of growth faltering among infants under six months, we examined the effectiveness of postnatal maternal or caregiver interventions on outcomes among infants between 0 and 6 months. We searched nine electronic databases from January 2000 to August 2021, included interventional studies, evaluated the quality of evidence for seven outcome domains (anthropometric recovery, child development, anthropometric outcomes, mortality, readmission, relapse, and non-response) and followed the GRADE approach for certainty of evidence. We identified thirteen studies with preterm and/or low birth weight infants assessing effects of breastfeeding counselling or education (n = 8), maternal nutrition supplementation (n = 2), mental health (n = 1), relaxation therapy (n = 1), and cash transfer (n = 1) interventions. The evidence from these studies had serious indirectness and high risk of bias. Evidence suggests breastfeeding counselling or education compared to standard care may increase infant weight at one month, weight at two months and length at one month; however, the evidence is very uncertain (very low quality). Maternal nutrition supplementation compared to standard care may not increase infant weight at 36 weeks postmenstrual age and may not reduce infant mortality by 36 weeks post-menstrual age (low quality). Evidence on the effectiveness of postnatal maternal or caregiver interventions on outcomes among infants under six months with growth faltering is limited and of 'low' to 'very low' quality. This emphasizes the urgent need for future research. The protocol was registered with PROSPERO (CRD42022309001).
Keywords: education intervention; failure to thrive; growth failure; growth faltering; infant; malnutrition; maternal; newborn; nutrition; underweight; wasting.