Background: The aim of the current study was to investigate the effects of prophylactic iron supplementation on the pregnancy outcome of nonanemic pregnant women in a sample of Iranian population.
Methods: This non-randomized clinical trial was conducted during a 2-year period in obstetrics clinics of Shiraz, southern Iran. We included a sample of singleton pregnancies registered in our clinics. Those with comorbidities were excluded. Serum ferritin was measured at baseline and participants were classified accordingly: those with normal serum ferritin levels (≥30 µg/dL) who received standard prophylactic iron supplementation during the pregnancy (Group 1); those who had minor thalassemia and elevated serum ferritin levels (≥30 µg/dL) who did not receive prophylactic iron supplementation or those with normal ferritin levels (≥30 µg/dL) who refused to receive iron supplementation due to gastrointestinal upset (Group 2); and those with iron deficiency anemia with low serum ferritin levels (<30 µg/dL) who received standard iron supplementation during pregnancy (Group 3). All the participants were followed to the delivery and maternal and neonatal outcomes were recorded and compared between three study groups.
Results: Overall we included 30 pregnant women in each group with mean age of the participants was 28.66 ± 6.02 years. There was no significant difference between three study groups regarding gestational age at delivery (p = 0.250), birthweight (p = 0.893), Apgar at 1 (p = 0.532) and 5 (p = 0.590) minutes, and route of delivery (p = 0.590). The overall rate of maternal complication of the pregnancy was comparable between the three study groups (p = 0.188). However, those in group 1, had significantly higher rate of gestational diabetes mellitus (GDM) when compared to other two groups (p = 0.038).
Conclusion: Prophylactic iron supplementation in pregnant women with normal ferritin levels is associated with increased risk of GDM. Other pregnancy and neonatal outcomes are not affected by the prophylactic iron supplementation.