Table 2.

Potential predictors (maternal and infant) of human milk intakes.

Factors that potentially predict human milk intakes		Explanation of potential impact or hypothesis	References
Maternal factors
	Breastfeeding self-efficacy	Mothers who have greater self-efficacy may have infants with higher intake.	Khresheh and Ahmad [68]
	Breast or chest trauma	Mothers who have experienced breast or chest trauma may have infants with lower intake.	Kraut et al [69] Haifeng et al [70] Stopenski et al [71] Leal et al [72] Holmgren et al [73]
	Cannabis	Mothers who use cannabis may have infants with lower intake.	Castro-Navarro et al [46]
	D-MERa	Mothers who experience D-MER (sudden, intense negative emotions that occur immediately before and during milk let-down) may have infants with lower intake.	Ureño et al [74]
	Early return of menses	Mothers who have had return of menses may have infants with lower intake.	Spencer et al [49]
	Education	Mothers who are more educated may have infants with higher intake.	Bandara et al [39] Haszard et al [31]
	Employment (current)	Mothers who are in current employment may have infants with lower intake.	Haszard et al [31]
	Following specific diet	Mothers who are consuming specific dietary patterns (eg, low fat, dairy-free, and vegetarian) may have infants with differing intake.	Spencer et al [49]
	Galactagogues or antigalactagogues	Mothers who are consuming galactagogues (a substance that is thought to increase milk volume) may have infants with higher intake, and mothers who are consuming antigalactagogues may have infants with lower intake.	Brodribb et al [75] Johnson et al [76]
	Hormonal birth control	Mothers who are taking hormonal birth control may have infants with lower intake.	Berens et al [77]
	Maternal BMI	Mothers with higher BMI may have infants with lower intake.	Hilson et al [40] Haszard et al [31]
	Maternal fat mass	Mothers who have higher fat mass may have infants with lower intake.	Diana et al [78]
	Parity	Mothers who have previously given birth may have infants with lower intake.	Whitehead et al [41]
	Previous breastfeeding experience	Mothers with previous breastfeeding success may have infants with higher intake, while those who did not have success previously may have infants with lower intake.	Huang et al [79]
	Maternal morbidities	Mothers who have medical conditions may have infants with lower intake.	Spencer et al [49]
	Maternal sleep	Hypothesis that maternal sleep may impact infant milk intake.	N/Ab
	Maternal use of medications	Mothers on certain medications may have infants with differing intake.	Farah et al [48]
	Mental health	Mothers who experience challenges with mental health may have infants with lower intake.	Spencer et al [49]
	Pain while breastfeeding	Mothers who experience pain while breastfeeding may have infants with lower intake.	McGuire [80]
	Smoking or nicotine	Mothers who use nicotine may have infants with lower intake.	Napierala et al [47]
	Stress	Mothers with higher levels of stress may have infants with lower intake.	Nagel et al [50]
Infant factors
	Age	It is known that infant intake varies over the course of lactation.	Bandara et al [39] da Costa et al [23] Whitehead et al [41] Brown et al [42] Haszard et al [31]
	Body weight	Infants with smaller body weight may have lower intake.	Bandara et al [39] Daniels et al [22] Agne-Djigo et al [43] Haisma 2003 [34] Haszard et al [31]
	Demand vs schedule feeding	Infants fed on demand rather than by schedule may have higher intake.	Dewey et al [44] Haszard et al [31]
	Growth trajectory	Infants with greater growth velocity may have higher intake.	Olga et al [36]
	Household temperature and humidity	Higher household temperature and humidity may be associated with higher intake.	Baby et al [81]
	Number of breast feeds (average per day)	Infants feeding more often may have higher intake.	Brown et al [42] Haszard et al [31]
	Sex	Male infants may have higher intake than female infants.	da Costa et al. 2010 [23]
	Spilling (average quantity)	Hypothesis that intake may differ in infants who spill.	N/A
	Term, preterm, or early term	Infants born early may have lower intake.	Lapillonne et al [82] Altuntas et al [83] Boies and Vaucher [84]

^aD-MER: dysphoric milk ejection reflex.

^bN/A: not applicable.