Gastrointestinal Complications of Ferrous Sulfate in Pregnant Women: A Randomized Double-Blind Placebo-Controlled Trial

Abstract

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.

The benefits and harms of oral iron supplementation in non-anaemic pregnant women: A systematic review and meta-analysis

“…Four papers reported on GI side effects 27,29,39,40 . These included nausea, vomiting, constipation, diarrhoea, abdominal pain, loss of appetite and heartburn.…”

Oral iron‐based interventions for prevention of critical outcomes in pregnancy and postnatal care: An overview and update of systematic reviews

“…A search strategy was prepared and launched in Medline and the Cochrane Library covering the period between February 2015 to February 2018 to update the evidence retrieved from the systematic reviews. The title and abstract of 230 records were screened and after 10 full‐texts were examined, two trials remained for inclusion . Jafarbegloo (2015) evaluated the gastrointestinal complications of ferrous sulfate in pregnant women whereas Zhao (2015) evaluated the effect of prenatal iron supplementation on maternal anemia, iron deficiency, and iron deficiency anemia.…”

“…The title and abstract of 230 records were screened and after 10 full‐texts were examined, two trials remained for inclusion . Jafarbegloo (2015) evaluated the gastrointestinal complications of ferrous sulfate in pregnant women whereas Zhao (2015) evaluated the effect of prenatal iron supplementation on maternal anemia, iron deficiency, and iron deficiency anemia. This update raised the number of our primary studies to 29 (Figure ).…”

Preparatory work for the update of the tolerable upper intake levels for iron

“…Five publications included pregnant women as study participants. In four of the studies, ferrous sulfate (Etheredge et al 2015;Jafarbegloo et al 2015;Chan et al 2009;Makrides et al 2003) and in one study, ferrous fumarate (Darwish et al 2019) was used as compounds for the intervention. The doses of iron applied were in the range between 20 (Makrides et al 2003) and 180 mg/day (Darwish et al 2019).…”