Erythrocyte zinc protoporphyrin testing in pregnancy.
BACKGROUND
To compare the usefulness of serum ferritin, hemoglobin and erythrocyte zinc protoporphyrin estimations as indicators of the need of iron supplementation in pregnancy.


METHODS
In 97 healthy pregnant women serum ferritin, hemoglobin and erythrocyte zinc protoporphyrin concentrations were measured at each trimester period. Iron supplementation was prescribed at hemoglobin values below 113 g/L.


RESULTS
Neither in the first nor in the second trimester differences in serum ferritin and erythrocyte zinc protoporphyrin values have been found between women who got iron therapy prescribed and women who did not get iron therapy, whereas already in the first trimester hemoglobin values were lower in the group that got iron therapy. These results indicate that hemodilution rather than iron deficiency determined which women got iron therapy. In the third trimester 14 out of 80 women without iron supplementation had depleted iron stores and a significant erythrocyte zinc protoporphyrin increase, indicating evolving iron deficiency anemia. However, only five of them showed hemoglobin levels below 113 g/L and got iron therapy. Low serum ferritin levels were found in 23% of the women at booking and in 92% in the third trimester. Serum ferritin levels neither predicted the development of iron deficient erythropoiesis nor of anemia.


CONCLUSIONS
Iron deficiency can neither be diagnosed nor predicted by serum ferritin or hemoglobin measurements at booking or later on in pregnancy. Erythrocyte zinc protoporphyrin measurements can be of help in determining which women have iron deficient erythropoiesis and may benefit by iron therapy.
Harthoorn-Lasthuizen
E J
EJ
Laboratory of Hematology, Bosch Medicentrum, 's-Hertogenbosch, The Netherlands.
Lindemans
J
J
Langenhuijsen
M M
MM
D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000175:diagnosis*; D015415:Biomarkers / Q000032:analysis; D003937:Diagnosis, Differential; D004912:Erythrocytes / Q000737:chemistry; D005260:Female; D005293:Ferritins / Q000097:blood*; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000175:diagnosis*; D011524:Protoporphyrins / Q000097:blood*; D012680:Sensitivity and Specificity; D015032:Zinc
D015415:Biomarkers; D006454:Hemoglobins; D011524:Protoporphyrins; D005293:Ferritins; D015032:Zinc