Fleming 1974.

Methods	RCT with randomisation by blocks of 50 consecutive participants into 5 arms.
Participants	146 consecutive pregnant women attending a public antenatal clinic in Western Australia before the 20th week of gestation who had not received iron supplements and were willing to participate. Women with Hb < 100.0 g/L were excluded.
Interventions	Participants were randomly assigned in sequences of 50 to 1 of the 5 interventions groups: group 1 received placebo; group 2 received 60 mg of elemental iron (as ferrous sulphate); group 3 received 500 μg (0.5 mg) of folic acid; group 4 received 60 mg of elemental iron (as ferrous sulphate) and 500 μg (0.5 mg) of folic acid; group 5 received 60 mg of elemental iron (as ferrous sulphate) and 5000 μg (5 mg) of folic acid. Supplementation with iron was from 20th week of gestation until delivery. All women had received 50 mg of ascorbic acid daily from the first visit until the 20th week. Setting and health worker cadre: the intervention was performed by obstetricians at a public antenatal clinic in western Australia. Patients were of a low SES.
Outcomes	Hb, serum and red cell folate, serum vitamin B12 at first attendance, and at 20, 28, 35 weeks and at delivery, and 6 weeks postpartum; pregnancy complications, anaemia defined as Hb lower than 100 g/L, premature delivery, abortion, compliance; birthweight, placental weight, Apgar score at delivery (full outcome data were not reported for group 5, which received a higher dose of folic acid).
Notes	More than 20% of the women were lost to follow‐up. We decided not to include outcome data for mean Hb at term, as the SDs provided in the paper represent a single SD for all groups and this assumes that distributions were similar in each treatment group. Gestational age at start of supplementation: late gestational age (supplementation started at or after 20 weeks' gestation). Anaemic status at start of supplementation: mixed/unspecified anaemia status. Daily iron dose: higher daily dose (60 mg elemental iron). Iron release formulation: normal release preparation/unspecified. Iron compound: ferrous sulphate. Malaria setting: non‐malarial setting. As of 2011: Malaria: no risk.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"they were allotted according to randomised sequences of 50."
Allocation concealment (selection bias)	Unclear risk	Not clear, women were provided with colour‐coded packages which identified the regimens.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	It was stated that the contents of the treatment packages were not known to women or investigators until after the completion of the trial.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Laboratory outcomes, women with anaemia excluded post randomisation although loss appeared balanced across groups.
Incomplete outcome data (attrition bias) All outcomes	High risk	146 women randomised, 89 women completed the trial and women were removed from the trial for reasons that may have related to outcomes (e.g. women developed anaemia).
Selective reporting (reporting bias)	Unclear risk	There was high attrition in this trial and data were not reported for all treatment groups.
Other bias	Unclear risk	No other bias apparent.