TABLE 1.

Inclusion criteria for study selection, mapped on to PEO criteria

Population	Exposure	Outcome
Maternal age over 18 Infant born full term (>37 weeks gestation) Infants born of a healthy weight (>2,500 g) Singleton infants, only Maternal absence of clinically diagnosed mental distress e.g., postnatal depression, postnatal anxiety, postnatal psychosis, prenatal anxiety, or prenatal depression, unless controlled for in analysis Absence of maternal condition(s) which would otherwise affect ability to breastfeed, such as breast reduction surgery; pituitary dysfunction; untreated tuberculosis; hepatitis B and C; active herpes lesions; human immunodeficiency virus (HIV); and substance abuse (Sheknows, 2007) No feeding, physical, or mental congenital irregularities in infant which would otherwise affect feeding ability, for example, tongue tie, lactose intolerance, cleft lip	Studies must have been conducted in a developed country, as defined by the Statistical Annex (Country Classification, 2014) Guilt and/or shame must be explicitly explored in the context of postnatal infant feeding experiences (i.e., formula and breastfeeding intention, initiation, duration, method at time of investigation, and qualitative experiences with these outcomes) Data collected in the first 6 months of life Guilt and/or shame must be explicitly explored in study results section, either in thematic analysis or as an outcome variable	Examination of breastfeeding and/or combination feeding, and/or formula feeding initiation, exclusivity, and duration. Qualitative experiences of infant feeding Primary data collection Written in any language Grey literature and dissertations/theses Cross‐sectional and longitudinal designs Qualitative and quantitative methodologies