The impact of different doses of oral iron supplementation during pregnancy: a pilot randomized trial.
Stanworth SJ., Churchill D., Sweity S., Holmes T., Hudson C., Brown R., Lax S., Murray J., Spiby H., Roy N., Farmer A., Gale C., Crayton E., Lorencatto F., Griffiths J., Mullings J., Last S., Knight M.
The burden of iron-deficiency anemia remains significant during pregnancy. Oral iron is first-line medication, but there is uncertainty about a range of factors including adherence and side-effects of different doses. We conducted a pilot randomized trial to investigate the impact of different doses of oral iron supplementation started early in pregnancy, in non-anemic women, for four main outcomes; recruitment and protocol compliance, adherence, maintenance of maternal hemoglobin and side-effects. Participants at antenatal clinic visits were allocated to one of three trial arms, in a 1:1:1 ratio, as 200mg ferrous sulphate daily, alternate days or three-times per week, with follow-up to delivery. Baseline characteristics of 300 recruited participants were well matched between trial arms. The mean proportion of tablets taken as expected per participant was 82.5% overall (72.3%, 89.6% and 84.5% for the daily, alternate days and three-times a week arm, respectively). There was a lower overall adherence rate in the daily arm (47%) compared with alternate days (62%) and three times per week (61%). Reduction in hemoglobin between randomization and 28 weeks appeared smaller for the daily arm. A range of side-effects were commonly reported at baseline before starting interventions, and by later antenatal visits. Many side effects of iron overlapped with normal pregnancy symptoms. A daily iron dosing schedule might give the best opportunity for delivering an adequate iron load during pregnancy in non-anemic women. Further randomized trials powered on clinical outcomes are needed to establish the clinical effectiveness of oral iron supplementation to prevent iron deficiency anemia. (ISRCTN12911644).