Doubling the Iron Dose VS Single Dose Iron Supplementation to Prevent Iron Deficiency Anemia (IDA) in Twin Pregnant Women: A Randomized Controlled Trial

Iron deficiency anemia (IDA) is a very prevalent condition in pregnancy, affecting nearly 18% of all pregnant women during all three trimesters, with as many as 29%of women affected during the third trimester.

In twin pregnancies, the maternal iron demands are magnified, estimated at 1.8 times more than in singleton pregnancies due to greater maternal red blood cell mass and plasma volume expansion as well as increased fetal and placental requirements. Thus, maternal hemoglobin (Hgb) in multiple pregnancies is lower in all trimesters compared with singleton gestations, with a rate of IDA estimated to be 2.4 to even 4 times higher.

Expert opinion relying on the increased risk for micronutrient deficiency in twin pregnancies recommends supplementation of iron beyond that contained in a typical prenatal vitamin. Moreover, some experts support doubling the dose of multivitamins containing 30 mg of elemental iron during the second and third trimesters of a twin pregnancy, regardless of maternal Hgb and ferritin concentrations.

With a lack of randomized controlled trials assessing the adequacy of iron supplements on twin pregnancy, various recommendations are based on level 3 clinical expert opinions at most. The purpose of our study was to assess the efficacy of a single versus a double daily iron supplement dose in iron deficient women with twin pregnancies. Determining the effect of this intervention on maternal iron stores and immediate neonatal outcome measures will assist in defining evidence based recommendations for prenatal care.