Pita Martin 1999.

Methods	RCT 3‐arm trial.
Participants	203 healthy pregnant women with normal blood pressure at first visit, attending antenatal care clinic at Diego Paroissien Hospital in the Province of Buenos Aires, Argentina were included in the study, but in this review only 41 women who were randomised and completed the study were included in the analysis.
Interventions	Participants were assigned to 1 of 3 groups: group 1 received 60 mg of elemental iron (as ferrous fumarate) daily; group 2 received 60 mg elemental iron (as ferrous fumarate) every 3 days; and group 3 received no treatment. Supplementation started at 8‐28 wks until 34‐37 wks of gestation. Setting and health worker cadre: the intervention was performed by physicians at the Diego Paroissien Hospital in the Matanza Provincia of Buenos Aires, Argentina.
Outcomes	Maternal: Hb, HCT, erythroporphyrin, serum ferritin concentration at baseline and at 34‐37 wks' gestation, premature birth. Infant: birthweight. Laboratory method for ferritin concentration: ELISA (Boehringer Lab).
Notes	Unsupervised. Women from control group (group 3) were not assigned randomly. These women were recruited but due to delays in the acquisition of the iron tablets and the progression of their pregnancies without supplementation they were left as controls in the study. This study is used only for comparison between intermittent and daily iron supplementation (group 2 vs group 1). Compliance not reported. 1. By gestational age at start of supplementation: unspecified gestational age or mixed gestational ages at the start of supplementation. 2. By anaemia status at baseline:unspecified/mixed anaemia status at start of supplementation. 3. By weekly iron dose in the group receiving intermittent supplementation: low weekly dose of iron in the intermittent group (120 mg elemental iron or less per wk). 4. By release speed of iron supplements: not specified/unreported/unknown. 5. by bioavailability of the iron compound relative to ferrous sulphate: equivalent or lower: ferrous fumarate; 6. By intermittent iron supplementation regimen: other intermittent regimens (every 3 days). 7. By malaria endemicity of the area in which the trial was conducted: not specified/unreported/unknown. Study carried out in malaria risk‐free parts of countries that has malaria risk in other parts. As of 2011: malaria risk due exclusively to Plasmodium vivax is very low and is confined to rural areas along the borders with Plurinational State of Bolivia (lowlands of Salta province) and with Paraguay (lowlands of Chacoand Misiones provinces). Source of funding: Universidad de Buenos Aires, Argentina (subsidio BA 086).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Inadequate ‐ quasi‐randomised. Uneven group size.
Allocation concealment (selection bias)	High risk	The medical doctor had the list of the assignments for the coming participants.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Women and medical staff would be aware of treatment allocation (personal communication).
Blinding of outcome assessment (detection bias) Laboratory outcomes	Low risk	Laboratory outcomes were unlikely to have been affected by lack of blinding.
Blinding of outcome assessment (detection bias) Side effects and compliance	Unclear risk	Side effects not reported (not clear if this information was collected).
Incomplete outcome data (attrition bias) All outcomes	High risk	Inadequate. More than 20% lost to follow‐up. 203 randomised but analysis was for only 88 women who completed the trial (57% attrition). It was not clear how many women were randomised to each group, at follow‐up the size of the control group was much larger than the intervention groups: control n = 47, daily group n = 29 and intermittent group n = 12.
Selective reporting (reporting bias)	Unclear risk	There is insufficient information to permit judgement.
Other bias	High risk	The participants were all added to the control group as the iron supplements had not arrived at the time of the study initiation.