Study	Reason for exclusion
Australia 1986a	No clinical outcomes reported. Participants: 58 primigravid women. Intervention: one week of either high salt or low salt diet. Study design: 'assigned randomly'.
Australia 1986b	No clinical outcomes reported. Participants: 40 primigravid women. Intervention: one week of either high salt or low salt diet. Study design: 'assigned randomly'.
UK 1958	Not a randomised trial. Quasi random, using alternate allocation of women attending clinic. Participants: 2077 women at booking clinic, 58 excluded. Intervention: high salt diet with advice to add salt to diet and eat salty food versus low salt with advice to avoid adding salt to food and not to eat salty food.
UK 1961	Not a randomised trial. Allocation by ward and by consultant. Participants: 739 women with high blood pressure, oedema and proteinuria. Excluded if <24 hours from admission to delivery. Interventions: 2g salt versus 10g versus 25g.
USA 1961	Not a randomised trial. Quasi random using alternate allocation. Participants: 48 women with pre‐eclampsia. Interventions: 1‐2g salt versus 10‐12g.