Iron status and pregnancy in a northern Canadian population: relationship to diet and iron supplementation

To determine the extent of iron deficiency, the prognostic value of prenatal ferritin levels and the desirability of prenatal iron supplementation in the western Canadian arctic, dietary iron intake was determined in 171 women and ferritin levels determined in 121 women during pregnancy, 79 at delivery and 77 postnatally, as well as in 65 of their infants at birth and 74 postnatally. Iron deficiency (ferritin < 15 ng/ml) was present in 34% of women during the first two trimesters, 25% (20/79) at delivery and in 51.7% (15/29) of mothers and 31% (9/29) of infants beyond four months after delivery. Maternal follow-up ferritin levels correlated poorly with dietary iron intake but well with prenatal ferritin levels, which appeared to be good predictors of the effectiveness of supplementation. Mean infant follow-up ferritin levels were 105.6 +/- 115.2 ng/ml with, and 46.7 +/- 63.5 without maternal prenatal supplementation (p = 0.03); maternal, 45.5 +/- 40.9 ng/ml with, and 12.8 +/- 9.2 without (p < 0.001). Measurement of prenatal ferritin levels to determine risk of iron deficiency and routine prenatal iron supplementation are recommended.