Prior to our study, there were no data available concerning the effects of either intravenous or oral iron supplementation for anaemia on postdelivery psychological and physical welfare of mothers, the quality of the bonding to the baby and the rate of developmental progress of the baby. We are reporting on 126 patients in a follow-up study of the effect of intravenous iron versus oral iron therapy on HRQoL during and after pregnancy. Our study demonstrates that there was an improvement in the self-assessed feeling of general health in both treatment groups from the prelabour period to all subsequent periods. Although the improvement was significantly greater during pregnancy in the intravenous iron group 4 weeks after commencement of trial treatment (p=0.001), the difference persisted in the subsequent measurement periods at a lesser magnitude that did not achieve statistical significance.
Regardless of treatment and regardless of which period was being considered, higher Hb and higher ferritin levels were associated with better baby sleep quality, a longer period of breastfeeding and a higher level of mothers’ general health.
The modified HRQoL questionnaire used in our study includes many useful and relevant aspects regarding general health, daily activities, levels of energy and depression. There was a substantial improvement of iron status in women who received intravenous iron compared to oral iron as demonstrated during the trial analysis (p<0.001). Limitations of our study include the modified questionnaire being in part a retrospective HRQoL evaluation that should ideally have been conducted within a shorter period of time. However, a correlation to a prospective evaluation of the studied subjects has been made in our study in order to overcome a possible recall bias. Therefore, we were able to minimise the number of retrospective questions, since the women were asked to recall their responses to each question at four different timepoints. The full SF-36 was impractical and may have been judged to be an excessive burden on the women. Thus, we attempted to provide a retrospective form of validation by showing that the clinical HRQoL questions in the physical domain, recorded prospectively at week 4 after trial, were most strongly associated with the Physical Component Scales of the recall of modified SF-36 at week 4 compared to the other timepoints. This indicates that the retrospective methodology was able to provide an acceptable degree of accuracy in the differentiation of HRQoL levels at different timepoints despite the concerns that may have arisen with this issue. The assumption being made is that the way those patients judge their physical and mental condition will be relatively stable over time,18
an assumption with which we agree may occur in patients with chronic diseases. However, this assumption may not hold for women during and after pregnancy. The expectations by the woman about how she should be feeling at the different stages of pregnancy, around the time of delivery, and when she is caring for one or more young infant or child may differ substantially at those different timepoints. At least in our analysis, the judgement the woman is making about how to answer the questions is likely to be the same for each timepoint, since she had made that judgement at one point in time: the repeated measures analysis compares each woman with herself, thus substantially reducing the impact of variation between women in this judgement. Thus, for the purpose of generating a hypothesis concerning iron status and quality of life, we believe that our methodology has been adequate. Another limitation of our study is the relatively small number of women studied. Nevertheless, prior to our study there was a lack of research that addressed HRQoL during and after pregnancy, and particularly the association between iron status and postnatal clinical depression as well as breastfeeding duration in our cohort of patients provides a novel finding and a basis for further research.
An incidental finding of our study was a trend for unfavourable mental health component outcomes for women with male babies. There is only a single report in the literature that addressed this issue and reported similar findings.19
Perhaps this may be explained with the observation that male babies are usually more active, and this may be associated with postnatal depression.19
However, due to lack of more detailed data, this issue should be addressed separately and studied in future research.
Owing to paucity of data regarding HRQoL during and after pregnancy, there are only limited data available from other studies. Jansen et al20
studied the effect of delivery and postpartum changes on the HRQoL. A cohort of 141 pregnant women were included in that study. HRQoL questionnaires were measuring the immediate effect of delivery on the quality of life. The HRQoL questionnaires were conducted less than 1 day after vaginal delivery and less than 2 days after delivery by caesarean section and compared to 3–6 weeks postdelivery for both groups.20
The study focused on patients’ HRQoL recovery after both delivery interventions. In that study,20
the different timepoints of completion of the questionnaire (immediately postdelivery and 3–6 weeks thereafter) may not necessarily reflect the HRQoL during pregnancy and subsequently after the postpartum period. Furthermore, the immediate questionnaire after delivery and at 3–6 weeks time in the postpartum period may have been influenced, at least in theory, by the event of delivery, in particular when complications occurred, as well as by the possible emotional and hormonal fluctuations during this period. It is worthwhile to note that the same study did not show any association between Hb and QoL; however, it did not investigate a possible effect of iron status on perceived HRQoL in conjunction with breastfeeding. This highlights our novel finding of the correlation between iron status and improved HRQoL during and after pregnancy.
In summary, we found a significant improvement in the general health of women who received intravenous iron (p<0.001), but this effect was found prominently 4 weeks after the intravenous iron treatment. The duration of breast-feeding was longer (p=0.04) in those women who had received intravenous iron. Women with better iron status were less downhearted (p=0.005) and less likely to develop postnatal clinical depression (p=0.003).
Our results indicate that it is worthwhile considering Hb and iron status as a surrogate marker for assessment of women's well-being, not only during pregnancy, but also during the postnatal period.
Further studies are warranted to confirm and extend our findings, and to determine outcomes in different populations with IDA in order to improve the estimates of the magnitude of the benefits of intravenous iron for the management of IDA.