Anemia in Pregnancy Calculator (WHO 2024 Hemoglobin Cutoffs)
Check whether a hemoglobin result in pregnancy means anemia, and how severe, using the WHO 2024 trimester-specific cutoffs with the adjustment for living at high altitude.
How it works
Adjusted Hb = measured Hb − altitude adjustment (0.4 g/dL at 500–999 m … 3.3 g/dL at 4,500 m or more) · anemia if adjusted Hb < 11.0 g/dL (1st and 3rd trimester) or < 10.5 g/dL (2nd trimester) · severe if < 7.0 g/dL
The 2024 WHO guideline on hemoglobin cutoffs defines anemia in pregnancy as hemoglobin below 110 g/L (11.0 g/dL) in the first and third trimesters and below 105 g/L (10.5 g/dL) in the second trimester, when blood volume expands most. Mild anemia is up to 1 g/dL below the cutoff, moderate anemia goes down to 7.0 g/dL and severe anemia is below 7.0 g/dL. People living above 500 m have naturally higher hemoglobin, so the WHO subtracts an altitude adjustment (in 500 m bands) before comparing — important in Andean cities such as Bogotá, Quito, La Paz or Cusco.
Worked example
A hemoglobin of 10.2 g/dL in the second trimester at sea level (altitude adjustment 0): the cutoff is 10.5 g/dL and the mild band is 9.5–10.4 g/dL, so the result is Mild anemia — talk to your prenatal care team about iron treatment.
Sources: WHO (2024) Guideline on haemoglobin cutoffs to define anaemia in individuals and populations · WHO recommendations on antenatal care for a positive pregnancy experience (2016)
Frequently asked questions
What hemoglobin level is normal in pregnancy?
According to the WHO (2024), hemoglobin of 11.0 g/dL or more in the first and third trimesters and 10.5 g/dL or more in the second trimester is not anemic. Hemoglobin normally dips in mid-pregnancy because plasma volume expands faster than red cells.
Why does altitude change the result?
At high altitude the body makes more hemoglobin to compensate for lower oxygen. A value that is normal in Lima may hide anemia in La Paz, so the WHO subtracts 0.4 g/dL at 500–999 m and up to 3.3 g/dL above 4,500 m before applying the cutoff.
What are the risks of anemia in pregnancy?
Moderate and severe anemia are linked to preterm birth, low birth weight, postpartum hemorrhage complications and fatigue. Iron deficiency is the most common cause, so iron and folic acid supplements are recommended throughout pregnancy.
How is anemia in pregnancy treated?
Most cases are treated with oral iron, often with extra folic acid, and a repeat blood test after a few weeks. Severe anemia or anemia late in pregnancy may need intravenous iron or other treatment decided by your doctor.
Related calculators
This calculator is for education only and does not replace your midwife, obstetrician or doctor. Contact your care team straight away about bleeding, fluid leaking, reduced baby movements, severe pain, fever or anything that worries you.