Iyengar 1975.

Methods	This RCT was conducted in Niloufer Hospital, Hyderabad (India). Women were alternatively assigned to treatment groups. Groups were matched on parity and height. The women were followed at monthly intervals until 32 weeks of gestation, once every 2 weeks until 36 weeks, and at weekly intervals thereafter until delivery.
Participants	Pregnant women between 20 and 28 weeks of gestation (n = 288).
Interventions	Group 1: no supplement (n = 52), Group 1: iron 60 mg (n = 96), Group 2: iron 60 mg + folic acid 500 µg (n = 134).
Outcomes	Birthweight (n = 230).
Notes	Pregant women belonging to low income less than Rs. 3000/‐ per month.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quote: "alternate subjects received either of therapy". Comment: probably not done.
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgement regarding allocation concealment.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Insufficient information to permit judgement regarding blinding.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Exclusion data with their reasons were not reported in the study. Attrition (> 20%) along with reasons were reported.
Selective reporting (reporting bias)	Low risk	Study seems to be free from selective reporting.
Other bias	Unclear risk	No other bias identified but insufficient information available to fully assess this 'Risk of bias' domain.