Gastrointestinal complications of ferrous sulfate in pregnant women : a randomized double-blind placebo-controlled trial

Abstract EN

Background : Some pregnant women discontinue iron supplements consumption due to Gastrointestinal (GI) complications, whereas pregnancy induces the same complications physiologically.

Objectives : The aim of the present study was to assess GI complications of ferrous sulfate in pregnant women.

Patients and Methods : This randomized, double-blind, placebo-controlled clinical trial was performed on 176 pregnant women referred to prenatal care clinic of Maryam Hospital from April 2011 to February 2012.

Pregnant women with Hb ≥ 13.2 gr/dL at 13th - 18th weeks of gestation were selected based on the inclusion criteria and were randomly assigned to the ferrous sulfate and placebo groups.

The ferrous sulfate group (n = 90) received a 50-mg ferrous sulfate tablet daily from the 20th week to the end of pregnancy and the placebo group (n = 89) received one placebo tablet in the same way.

All participants were visited twice at 24th - 28th and 32nd - 36th weeks to assess the GI complications as well as Hb level to determine the Hb changes in two groups.

Chi-square test, t-test and Kolmogorov-Smirnov test were used to analyze the data.

P value of < 0.05 and confidence level of 95% were considered as statistically significant.

Results : None of the GI complications were significantly different between the ferrous sulfate and placebo groups at 24th - 28th and 32nd - 36th weeks.

Hemoglobin drop lower than 10.5 gr/dL at 24th - 28th weeks or lower than 11 g/dL at 32nd - 36th weeks was not observed in any cases.

Conclusions : It can be concluded that GI complications in pregnant women using ferrous sulfate are mostly caused by physiologic changes of pregnancy rather than ferrous sulfate; therefore, it is not reasonable to stop using ferrous sulfate due to GI complications.