Gestational age was calculated from the first
day of last menstrual period or according to the
sonography which was performed in the first
months of pregnancy. Anemia was determined on
the basis of hemoglobin less than 10 mg/dl.
Anemia evaluation was performed in all the cases.
Complete blood count (CBC), Iron studies (iron,
total iron binding capacity) were performed for
excluding iron deficiency anemia and the anemia
of chronic disorders. Thalassemia was
diagnosed
according to CBC and standard hemoglobin
electrophoresis criteria in the first trimester: an
elevation of Hb A2 (equal or more than 3.5%)
demonstrated by electrophoresis and column
chromatography confirms the diagnosis of β-
thalassemia trait. Blood transfusions were given
only when hemoglobin (Hb) dropped significantly
(less than 7mg/dl) either due to pregnancy or any
other causes. Hemoglobin increased at least to 10
mg/dl with transfusion. According to American
College of Obstetricians and Gynecologists criteria
(9), folate supplement in each group (case and
control) was given 1mg orally daily.