Three-year follow-up of a randomised clinical trial of intravenous versus oral iron for anaemia in pregnancy

Abstract

Background: To date, there are no data available concerning the impact of iron therapy on the long-term well-being and health-related quality of life (HRQoL) in pregnancy.

Objective: To assess the long-term effect of iron therapy on HRQoL in pregnancy.

Design: This is a follow-up study conducted between January 2010 and January 2011 of an earlier randomised open-label clinical trial of intravenous and oral iron versus oral iron for pregnancy-related iron deficiency anaemia. We used a modified version of the SF-36 questionnaire together with the original prospective HRQoL data collected during and after pregnancy.

Participants and interventions: Of the original evaluable 183 pregnant Caucasian women randomised to receive oral iron or a single intravenous iron polymaltose infusion followed by oral iron maintenance, 126 women completed the follow-up HRQoL study.

Methods: The participants were followed up 4 weeks after treatment, predelivery and postdelivery for a median period of 32 months (range, 26-42) with a well-being and HRQoL questionnaire using a modified SF-36 QoL-survey and child growth charts as set by the Australasian Paediatric Endocrine Group (APEG).

Results: Patients who received intravenous iron demonstrated significantly higher haemoglobin and serum ferritin levels (p<0.001). There were strong associations between iron status and a number of the HRQoL parameters, with improved general health (p<0.001), improved vitality (physical energy) (p<0.001), less psychological downheartedness (p=0.005), less clinical depression (p=0.003) and overall improved mental health (p<0.001). The duration of breastfeeding was longer (p=0.046) in the intravenous iron group. The babies born in both groups recorded similarly on APEG growth chart assessments.

Conclusions: Our data suggest that HRQoL is improved until after pregnancy in anaemic pregnant women by repletion of their iron stores during pregnancy. About 80% of the intravenous iron group showed a maintained normal ferritin until delivery with long-term benefits. Further studies to confirm these findings are warranted.

Figure 1

Patients flow chart. *Fourteen patients were admitted late in labour, and no blood samples were taken before delivery. ^†The primary hypothesis examined the change in haemoglobin levels between the time of booking and immediately prior to delivery; an ‘intention-to-treat’ analysis was performed according to original randomisation group on those patients who had blood samples taken before delivery, whether or not the treatment was completed as per the protocol. ^‡Twenty-one patients withdrew from the trial treatments, and all but one of these patients agreed to continued collection of haematological and other trial data; eight patients gave no reason for withdrawal. ^§Five patients did not complete the intended treatments, but did not choose to withdraw themselves; three patients in the oral iron group were treated with intravenous iron when their haemoglobin was judged not to have responded adequately to oral iron, while one patient was unable to attend for intravenous iron treatment.

Figure 2

(A and B) Comparison of physical component scale of health-related quality-of-life (HRQoL) scores in the intravenous plus oral iron versus the oral iron group, and separate association with iron status. †Comparison of the effect of intravenous plus oral iron versus oral iron on physical (A) and mental (B) components of the HRQoL scores at different time periods (before starting iron, 4 weeks after starting iron, at delivery and when the mother responded to questionnaire), estimated using ordinal logistic regression adjusted for significant demographic confounders but not including iron status, corrected for repeated measures and multiple comparisons (Holm method). *The effect of iron status on physical component and mental component scores was estimated separately without including treatment group in the analysis. The timepoint ‘Later’ is referring to the postdelivery follow-up assessment.

Figure 3

Effect of IV plus oral iron versus oral iron on rate of cessation of breastfeeding.