Table 2.
Key characteristics and selected results of two randomised trials to assess the effect of supplementation with iron on maternal Plasmodium infection risk at birth
| Tanzania trial (Etheredge et al, 2015) | Kenya trial (Mwangi et al, 2015) | |
|---|---|---|
| n | 1500 | 470 |
| Study population and design features | ||
| Setting | Urban | Rural, poor |
| Malaria transmission | Low | High |
| Chemopreventiona | As per standard care | As per routine care |
| In possession of insecticide‐treated net | 88·5% iron group versus 88·9% placebo group | 15·2% iron group versus 15·9% placebo group |
| Duration of intervention | From ≤27 weeks of gestational age (by date of last menstrual period) until delivery | From 13 to 23 weeks of gestational age (by ultrasound examination) until 1 month postpartum |
| Iron‐deficient, anaemic women | Excluded | Included if haemoglobin concentration >90 g/l |
| HIV‐infected women | Excluded | Included |
| Intervention | 60 mg elemental iron as ferrous sulphate or placebo | 60 mg elemental iron as ferrous fumarate or placebo |
| Blinding to intervention | Tablets (do not mask iron taste) | Capsules, opaque |
| Adherence assessment | Monthly tablet counts | Swallowing of supplements was daily observed |
| Outcomes | ||
| Plasmodium infection risk at birthb |
6·7% iron group versus 6·5% placebo group Risk difference: 0·2% Risk ratio: 3%, 95% CI: −35% to 65% (P = 0·89) |
50·9% iron group versus 52·1% placebo group Risk difference: −1·2% (95% CI: −11·8% to 9·5%) |
| Mean birth weight | 3155 g versus 3137 g; difference: 26 g (P = 0·89) | Difference: 150 g, 95% CI: 56 g to 244 g (P = 0·002) |
| Preterm birth riskc |
15·0% iron group versus 16·5% placebo group Risk difference: −1·5% Risk ratio: −9%, 95% CI: −29% to 17% (P = 0·46) |
9·1% iron group versus 16·2% placebo group Risk difference: −7·1%, 95% CI: −13·2% to −1·1% (P = 0·02) |
a
Intermittent preventive treatment with sulfadoxine‐pyrimethamine.
b
Primary outcome, defined by histopathological examination and polymerase chain reaction (PCR) analysis of placental biopsies (Etheredge et al, 2015) or 1 or more positive results for (i) the presence of parasite lactate dehydrogenase (pLDH) or histidine‐rich protein II (HRP2) in plasma, or (ii) by placental histopathology, or (iii) P. falciparum DNA in maternal erythrocytes from venous or placental blood by PCR test (Mwangi et al, 2015).
c
Preterm birth: gestational age <37 weeks.