TABLE 4.

Reported biomarker values for umbilical cord blood¹

Biomarker	26–28 wk	29–31 wk	32–36 wk	37–41 wk	Reference
SF, µg/L	75 (44–117)	—	90 (45–142)	171 (121–259)	Sweet et al. (278)
				131 (90–238)	Sweet et al. (347)
				134 (40–310)	Chockalingam et al. (277)
				101	Siimes et al. (346)
sTfR, µg/dL	10.3 (7.5–16.5)	—	8.2 (5.4–12.5)	8.4 (6.4–10.6)	Sweet et al. (347)
				9.4 (6.7–10.8)	Sweet et al. (278)
ZPP/H, µmol/mol	122 ± 34	103 ± 18	122 ± 34	—	Juul et al. (348)

¹Values are medians (ranges) or means ± SDs. SF, serum ferritin; sTfR, serum transferrin receptor; ZPP/H, zinc protoporphyrin/heme ratio.