TABLE 3.

Summary of studies that have evaluated the effect of infant diets on the incidence of NEC¹

References	Study design	Population	Duration of intervention	Comparison groups	NEC, n (%)
182	RCT	500–1250 g	≤91 d old, hospital discharge, or 50% oral feeds (4 complete feeds/d) achieved	HM100, HM40, and BOV	HM100: 3 (4.5%); HM40: 5 (7.0%); and BOV: 11 (15.9%)*
76	RCT	500–1250 g	≤91 d old, hospital discharge, or 50% oral feeds (4 complete feeds/d) achieved	HM and BOV	HM: 1 (3%); BOV: 5 (21%)
75	SR—4 RCTs of relevance (76, 91–93)	500–1250, <1600, <1850, and <1500 g	≤91 d old, hospital discharge, or 50% oral feeds achieved (76); until weight reached 1800 g (91); until discharge or transfer, or 2000 g (92); and from the 10th day of life until 2000 g or illness requiring intravenous nutrition (93)	DHM and BOV	DHM: 3 (1.6%); BOV: 13; (7.6%)**
53	RCT	<33 wk GA and 700–1500 g	Until 29 d after fortification or hospital discharge	LE-HMF and PI-HMF	LE-HMF: 1 (1.5%); PI-HMF: 2 (3.2%)

¹*HM100 compared with BOV, P = 0.04; HM100 + HM40 compared with BOV, P = 0.02; and HM40 compared with BOV, P = 0.09. **DHM compared with BOV, P = 0.009. BOV, bovine milk–based preterm formula provided if MOM unavailable or bovine milk–based fortifier added when breast milk intake reached 100 mL/kg; DHM, donor human milk as sole diet; GA, gestational age; HM, pasteurized donor human milk plus human milk–based human milk fortifier; HM40, exclusive human milk diet, fortifier added when feeds reached 40 mL/kg; HM100, exclusive human milk diet, fortifier added when feeds reached 100 mL/kg; LE-HMF, liquid human milk fortifier with extensively hydrolyzed proteins; MOM, mother’s own milk; NEC, necrotizing enterocolitis; PI-HMF, powdered human milk fortifier with intact proteins; RCT, randomized controlled trial; SR, systematic review.

²In both the HM100 and HM40 groups, 1 NEC case was a protocol violator that had received some amount of bovine milk–based formula or fortifier.