Table 3.

Study characteristics of 20 included studies

Reference	Country	Sample	Design	Psychological factor(s)	Breastfeeding behaviour(s)	Quality score*
Bartok et al. 31	USA	Women birthing at medical centre	Cohort	Planned duration and general beliefs about BF	Duration	32
Bogen et al. 32	USA	Pregnant women volunteers	Observational	Planned IF method	Initiation and duration	34
Chapman et al. 23	USA	Pregnant women attending prenatal clinic	RCT	Confidence in ability to BF	Initiation and duration	32
Cordero et al. 33	USA	Mothers of macrosomic infants born at a hospital	Cohort	Planned IF method	Initiation	23
Guelinckx et al. 34	Belgium	Women birthing at a hospital	Cohort	Planned IF method, belief in breast milk's nutritional adequacy and sufficiency	Initiation and duration	29
Hauff et al. 19	USA	Pregnant women volunteers	Cohort	Planned IF method, planned duration, general beliefs about BF, belief about others' IF preferences, confidence in ability to BF and social knowledge	Initiation and duration	32
Hilson et al. 18	USA	Pregnant women in hospital database	Observational	Planned duration, general beliefs about BF, body image, confidence in ability to BF, factual knowledge and social knowledge	Duration	30
Jarlenski et al. 20	USA	Pregnant women volunteers	Cohort	Planned IF method, general beliefs about BF, belief about others' IF preferences, body image, confidence in ability to BF, BF in social environments, factual knowledge and social knowledge	Initiation and duration	31
Kair et al. 35	USA	Women birthing at one of three hospitals	Cohort	General beliefs about BF, belief about others' IF preferences, belief in breast milk's nutritional adequacy and sufficiency	Duration	35
Krause et al. 36	USA	Women attending one of three obstetric clinics and volunteers	Observational	Expected outcomes of BF for weight and depressive symptoms	Initiation, duration and intensity	28
Masho et al. 37	USA	Women birthing in a hospital	Cohort	Depressive symptoms and stress	Initiation	32
Mehta et al. 38	USA	Pregnant women attending a hospital	Cohort	Depressive symptoms, stress and anxiety	Initiation and duration	32
Mok et al. 39	France	Women birthing at a hospital	Case–control	Belief in breast milk's nutritional adequacy and sufficiency and BF in social environments	Initiation and duration	31
Newby et al. 40	Australia	Pregnant women attending a public event for families	Cohort	Planned IF method, planned duration, confidence in ability to BF and BF in social environments	Duration	31
Ng et al. 41	Australia	Women birthing at one of three hospitals	Cohort	Psychological distress	Duration	32
O'Sullivan et al. 42	USA	Pregnant women volunteers	Cohort	Planned duration, general beliefs about BF, belief about others' IF preferences, confidence in ability to BF and social knowledge	Duration	32
Swanson et al. 43	Scotland	Women birthing at a hospital	Cohort	Body image, psychological distress	BF status	34
Visram et al. 44	Canada	Women birthing in one of four hospitals	Cohort	Planned IF method	BF status	32
Zanardo et al. 45	Italy	Pregnant women attending a tertiary medical centre	Case–control	Body image	BF at discharge and cessation	28
Zanardo et al. 46	Italy	Pregnant women attending a tertiary medical centre	Case–control	Eating disorder symptoms	BF at discharge and cessation	28

^* Quality score out of a possible 36.

BF, breastfeed/ing; IF, infant feeding; RCT, randomized controlled trial.