Red cell biomarkers
| Sampling time point | Lower reference limit (90% CI) | Upper reference limit (90% CI) | RIW 95% | N | Comparison with other published data lower–upper value (RIW) | |
| Hb (g/L) | ||||||
| Umbilical cord | 116 (115 to 121) | 189 (184 to 202) | 73 | 391 | 146–189 (43) | 24 |
| 135–195 (60) | 6 | |||||
| 48–118 hours | 147 (139 to 157) | 218 (213 to 234) | 71 | 152 | 145–225 (80) capillary | 6 |
| 125–210 (85) | 11 | |||||
| 134–221 (87) | 5 | |||||
| 4 months | 99 (97 to 101) | 130 (128 to 132) | 31 | 352 | 103–141 (38) | 25 |
| 97–133 (36) | 5 | |||||
| 95–135 (40) | 6 | |||||
| 12 months | 104 (99 to 106) | 134 (131 to 139) | 30 | 188 | 113–141 (28) | 25 |
| 107–134 (27) | 4 | |||||
| 100–135 (35) | 5 | |||||
| 105–135 (30) | 6 | |||||
| Adult RI | Women 117–153 (36), men 134–170 (36) | 37 | ||||
| Haematocrit (L/L) | ||||||
| Umbilical cord | 0.36 (0.35 to 0.37) | 0.57 (0.56 to 0.59) | 0.21 | 391 | 0.44–0.58 (0.14) | 24 |
| 0.42–0.60 (0.18) | 6 | |||||
| 48–118 hours | 0.42 (0.39 to 0.44) | 0.62 (0.60 to 0.65) | 0.20 | 152 | 0.45–0.67 (0.22) capillary | 6 |
| 0.35–0.60 (0.25) | 11 | |||||
| 0.38–0.64 (0.26) | 5 | |||||
| 4 months | 0.29 (0.28 to 0.29) | 0.37 (0.37 to 0.38) | 0.08 | 347 | 0.32–0.44 (0.12) | 25 |
| 0.28–0.40 (0.12) | 5 | |||||
| 0.29–0.41 (0.12) | 6 | |||||
| 12 months | 0.31 (0.30 to 0.31) | 0.39 (0.39 to 0.41) | 0.08 | 188 | 0.33–0.41 (0.08) | 25 |
| 0.30–0.39 (0.09) | 4 | |||||
| 0.29–0.40 (0.11) | 5 | |||||
| 0.33–0.39 (0.06) | 6 | |||||
| Adult RI | Women 0.35–0.46 (0.11), men 0.39–0.50 (0.11) | 37 | ||||
| MCV (fL) | ||||||
| Umbilical cord | 97 (95 to 98) | 118 (117 to 120) | 21 | 391 | 102–118 (16) | 24 |
| 98–118 (20) | 6 | |||||
| 48–118 hours | 91 (85 to 92) | 107 (105 to 115) | 16 | 152 | 101–119 (18) | 26 |
| 91–116 (25) | 5 | |||||
| 95–121 (26) capillary | 6 | |||||
| 4 months | 71 (69 to 72) | 85 (84 to 86) | 14 | 347 | 76–97 (21) | 25 |
| 70–90 (20) | 5 | |||||
| 74–108 (34) | 6 | |||||
| 12 months | 70 (69 to 71) | 83 (82 to 84) | 13 | 188 | 71–85 (14) | 25 |
| 72–85 (13) | 4 | |||||
| 68–86 (18) | 5 | |||||
| 70–86 (16) | 6 | |||||
| Adult RI | 82–98 (16) | 37 | ||||
| MCHC (g/L) | ||||||
| Umbilical cord | 303 (300 to 310) | 352 (350 to 354) | 49 | 391 | 306–342 (36) | 24 |
| 300–360 (60) | 6 | |||||
| 48–118 hours | 343 (339 to 345) | 372 (367 to 373) | 29 | 152 | 305–378 (73) | 5 |
| 290–370 (80) capillary | 6 | |||||
| 4 months | 328 (327 to 331) | 363 (360 to 365) | 35 | 347 | 312–372 (60) | 5 |
| 300–360 (60) | 6 | |||||
| 12 months | 323 (323 to 326) | 353 (352 to 355) | 30 | 188 | 321–365 (44) | 25 |
| 330–380 (50) | 4 | |||||
| 312–370 (58) | 5 | |||||
| 300–360 (60) | 6 | |||||
| Adult RI | 317–357 (40) | 37 | ||||
| MCH (pg) | ||||||
| Umbilical cord | 32 (31 to 33) | 39 (38 to 39) | 7 | 391 | 33–38 (5) | 24 |
| 31–37 (6) | 6 | |||||
| 48–118 hours | 32 (31 to 33) | 38 (37 to 40) | 6 | 152 | 34–40 (6) | 26 |
| 32–38 (6) | 5 | |||||
| 31–37 (6) | 6 | |||||
| 4 months | 24 (23 to 25) | 29 (29 to 30) | 5 | 347 | 26–30 (4) | 26 |
| 24–30 (6) | 5 | |||||
| 25–35 (10) | 6 | |||||
| 12 months | 23 (23 to 24) | 28 (28 to 29) | 5 | 188 | 24–30 (6) | 25 |
| 25–31 (6) | 4 | |||||
| 23–29 (6) | 5 | |||||
| 23–31 (8) | 6 | |||||
| Adult RI | 27–33 (6) | 37 | ||||
| RET (×109/L) | ||||||
| Umbilical cord | 99 (91 to 106) | 240 (229 to 267) | 141 | 391 | 99–228 (129) | 24 |
| 48–118 hours | 79 (67 to 95) | 275 (250 to 300) | 196 | 152 | 24–124 (100) | 27 |
| 97–316 (219) | 26 | |||||
| 218–419 (201) | 6 | |||||
| 4 months | 20 (17 to 22) | 65 (62 to 68) | 45 | 347 | 34–83 (49) | 27 |
| 25–82 (57) | 26 | |||||
| 12 months | 18 (11 to 20) | 66 (59 to 95) | 48 | 187 | 34–83 (49) | 27 |
| 27–98 (71) | 30 | |||||
| 18–65 (47) | 38 | |||||
| Adult RI | 28–120 (92) | 37 | ||||
| RBC (×1012/L) | ||||||
| Umbilical cord | 3.4 (3.1 to 3.5) | 5.4 (5.3 to 5.4) | 2.0 | 391 | 3.9–5.5 (1.6) | 6 |
| 48–118 hours | 4.2 (3.7 to 4.4) | 6.2 (6.1 to 6.9) | 2.0 | 152 | 4.1–7.1 (3.0) | 26 |
| 3.9–6.2 (2.3) | 5 | |||||
| 4.0–6.6 (2.6) capillary | 6 | |||||
| 4 months | 3.6 (3.4 to 3.7) | 4.9 (4.8 to 5.0) | 1.3 | 347 | 3.5–5.1 (1.6) | 25 |
| 3.3–5.0 (1.7) | 5 | |||||
| 3.1–4.5 (1.4) | 6 | |||||
| 12 months | 3.9 (3.9 to 4.0) | 5.3 (5.1 to 5.4) | 1.4 | 188 | 4.1–5.3 (1.2) | 25 |
| 4.0–5.6 (1.6) | 4 | |||||
| 3.9–5.2 (1.3) | 5 | |||||
| 3.7–5.3 (1.6) | 6 | |||||
| Adult RI | Women 3.9–5.2 (1.3), men 4.2–5.7 (1.5) | 37 | ||||
| Ret-He (pg) | Data for Ret-He for the County Hospital of Halland cohort have already been published28 but using different reference interval methodology. Compared with the previous study, we here use alternative exclusion criteria, include the Karolinska University Hospital cohort, harmonise calculations using robust statistical methodology and add calculations of 90% CIs to cohere with current guidelines. | |||||
| Umbilical cord | 28 (27 to 28) | 39 (38 to 40) | 11 | 388 | 27–36 (9) | 28 |
| 48–118 hours | 28 (25 to 29) | 38 (37 to 41) | 10 | 152 | 31–37 (6) | 26 |
| 28–38 (10) | 28 | |||||
| 4 months | 25 (22 to 26) | 34 (33 to 34) | 9 | 346 | 27–32 (5) | 26 |
| 26–33 (8) | 28 | |||||
| 12 months | 24 (21 to 25) | 33 (33 to 36) | 9 | 187 | 26–33 (8) | 30 |
| 25–34 (9) | 28 | |||||
| 28–33 (6) | 29 | |||||
| Adult RI | 28–35 (7) | 39 | ||||
Lower and upper reference limits calculated as the 2.5th and 97.5th percentiles from N individuals. RIWs, reference limits published elsewhere and values for adults are shown for comparison.
Hb, haemoglobin; MCH, mean cell haemoglobin; MCHC, mean cell haemoglobin concentration; MCV, mean cell volume; RBC, red blood cell; RET, reticulocyte count; Ret-He, reticulocyte haemoglobin equivalent; RIW, reference interval width.