[Effects of iron-deficiency anemia on placenta and birth weight].

Objective: To determine placenta alterations in iron deficiency anemia cases and the effect of this condition on birthweight.

Patients, Material And Methods: One hundred and fifty three women with term-pregnancy and their newborns were included. Patients with iron deficiency anemia were those with an hemoglobin of less than 11.0 g/dL and serum ferritin below 12 micrograms/L. Outcome variables were: placenta weight, placenta weight/newborn weight ratio, macroscopic and microscopic alterations on placenta, weight and height of the newborn.

Results: The frequency of iron deficiency anemia was determined in 26 patients, 17%. The placenta weight in the group of women with a diagnosis of iron deficiency anemia was 558 +/- 105 g and in the group of women without this diagnosis 527 +/- 107 g (p = 0.18). Placenta weight/newborn weight ratio was higher in the anemia group patients (p = 0.04). The most frequent microscopic lesions observed were intervillous thrombosis, infarcts and fibrosis. The birthweight and length of newborn was similar in both groups.

Conclusion: A trend towards an increase in placenta weight and in the placenta weight/newborn weight ratio in patients fulfilling the anemia criteria was observed, but a significant effect on the weight and height of the newborn was not determined, suggesting that the changes present in the placenta would be enough to ensure a fetal growth.