Table 2.

Tests used to diagnose iron deficiency in pregnancy

Test	Advantages	Limitations
Standard iron studies Iron Transferrin saturation Ferritin	Readily available; widely used in research studies Low ferritin diagnostic of iron deficiency	Parameters are subject to substantial physiological change during pregnancy
Non-standard iron studies Circulating transferrin	Likely of value in determining ID Probably little change	Not widely available; limited data in pregnancy
receptor	during pregnancy
Reticulocyte haemoglobin content
Zinc protoporphyrin
%hypochromic RBC
Hepcidin	Key determinant in iron absorption	Difficult to measure and interpret; very limited data in pregnancy
Bone marrow	Direct measure of iron presence in bone marrow	Subject to physiological change during pregnancy
	Recognised gold standard

RBC: red blood cells; ID: iron deficient