II. Calculation
III. Normal Values per age (-2 SD to +2 SD)
- Birth: 42 to 64% (mean 51%)
- Age <1 month: 31 to 67% (mean 44%)
- Age 1-2 months: 28 to 55% (mean 35%)
- Age 2-6 months: 28 to 42% (mean 36%)
- Age 0.5 - 2 years: 33 to 40% (mean 36%)
- Age 2 to 6 years: 34 to 40% (mean 37%)
- Age 6-12 years: 35 to 45% (mean 40%)
- Female
- Age 12-18 years: 36 to 46% (mean 41%)
- Age >18 years: 36 to 44% (mean 41%)
- Male
- Age 12-18 years: 37 to 49% (mean 43%)
- Age >18 years: 41 to 50% (mean 47%)
IV. Anemia Cutoffs
- Men
- Age 12-14 years: <37.3%
- Age 15-17 years: <39.7%
- Age >17 years: <38% (WHO) or <39.9% (CDC)
- Women (Non-pregnant, non-lactating)
- Age 12-14 years: <35.7%
- Age 15-17 years: <35.9%
- Age >17 years <35% (WHO) or <35.7% (CDC)
- Women in Pregnancy (CDC Guidelines <5th percentile)
- First Trimester: <33.0%
- Second Trimester: <32.0%
- Third Trimester: <33.0%
- Children (CDC Guidelines <5th percentile)
- Age 1-2 years: <32.9%
- Age 2-5 years: <33.0%
- Age 5-8 years: <34.5%
- Age 8-11 years: <35.4%
- Infants (2 S.D. below mean)
- Term (cord blood): <42% (mean 51%)
- Newborn (1-3 days): <56 (mean 45%)
- Age 2 weeks: <53% (mean 41%)
- Age 1 month: <44% (mean 33%)
- Age 2 months: <35%(mean 28%)
- Age 6 months: <36% (mean 31%)
- Reference
- Shilkofski (2005) Harriet Lane Handbook, 17th ed, Mosby, p. 337
V. Increased Hematocrit
- Erythrocytosis
- Profound diuresis
- Hemoconcentration
- Polycythemia Vera
- High Altitude
VI. Decreased Hematocrit
- See Anemia
- Plasma Volume expansion with constant RBC mass
- Pregnancy
- Recovery stage after Acute Hemorrhage
- Hematocrit lags blood loss (not reliable indicator)
VII. References
- Behrman (2000) Nelson Pediatrics, Saunders, p. 1462
- Johnson (1993) Harriet Lane Handbook, Mosby, p. 231
- (1998) MMWR Morb Mortal Wkly Rep 47:1-29 [PubMed]