Comparison 2. Routine high‐dose calcium supplementation in pregnancy by hypertension risk.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 High blood pressure (with or without proteinuria)	12	15470	Risk Ratio (M‐H, Random, 95% CI)	0.65 [0.53, 0.81]
1.1 Low‐risk women	8	15143	Risk Ratio (M‐H, Random, 95% CI)	0.71 [0.57, 0.89]
1.2 High‐risk women	4	327	Risk Ratio (M‐H, Random, 95% CI)	0.47 [0.22, 0.97]
2 Pre‐eclampsia	13	15730	Risk Ratio (M‐H, Random, 95% CI)	0.45 [0.31, 0.65]
2.1 Low‐risk women	8	15143	Risk Ratio (M‐H, Random, 95% CI)	0.59 [0.41, 0.83]
2.2 High‐risk women	5	587	Risk Ratio (M‐H, Random, 95% CI)	0.22 [0.12, 0.42]
3 Preterm birth	11	15275	Risk Ratio (M‐H, Random, 95% CI)	0.76 [0.60, 0.97]
3.1 Low‐risk women	7	14707	Risk Ratio (M‐H, Random, 95% CI)	0.84 [0.67, 1.05]
3.2 High‐risk women	4	568	Risk Ratio (M‐H, Random, 95% CI)	0.45 [0.24, 0.83]
4 Admission to neonatal intensive care unit	4	13406	Risk Ratio (M‐H, Fixed, 95% CI)	1.05 [0.94, 1.18]
4.1 Low‐risk women	3	13343	Risk Ratio (M‐H, Fixed, 95% CI)	1.06 [0.94, 1.19]
4.2 High‐risk women	1	63	Risk Ratio (M‐H, Fixed, 95% CI)	0.29 [0.03, 2.48]
5 Stillbirth or death before discharge from hospital	11	15665	Risk Ratio (M‐H, Fixed, 95% CI)	0.90 [0.74, 1.09]
5.1 Low‐risk women	8	15153	Risk Ratio (M‐H, Fixed, 95% CI)	0.90 [0.74, 1.09]
5.2 High‐risk women	3	512	Risk Ratio (M‐H, Fixed, 95% CI)	0.39 [0.02, 9.20]