3. Cross‐tabulation of main intervention strategy by comparison type, for studies reporting the primary outcome.

		Comparison type			Total
		Usual care	Less intensive intervention	Alternative intervention
Main intervention strategy	Counselling	32	18	1	51
	Health education	5	5	1	11
	Feedback	2	4	0	6
	Incentives	5	4	4	13
	Social support	4	10	0	14
	Exercise	0	1	0	1
	Other (Diss)	0	1	0	1
Total		48	43	6	97

This includes specific smoking cessation strategies and broader maternal health interventions with a smoking cessation component (C = 2, F = 1, I = 1, SS = 7)