Characteristics of studies included in the qualitative synthesis (n = 81), overall quantitative synthesis (n = 17), and quantitative synthesis with only studies using the WHO’s definition for PPH or severe PPH (n = 7)
| Studies included in qualitative synthesis . | Studies included in overall quantitative synthesis . | Studies using the WHO's definition for PPH and severe PPH included in quantitative synthesis . | ||||
|---|---|---|---|---|---|---|
| . | Number of studies . | Number of pregnant women . | Number of studies . | Number of pregnant women . | Number of studies . | Number of pregnant women . |
| Total | 81 | 20 317 287 | 17 | 26 654 | 7 | 16 611 |
| Study location | ||||||
| Europe | 21 | 219 215 | 8 | 15 772 | 7 | 16 611 |
| North America | 10 | 271 588 | 2 | 2894 | 0 | 0 |
| South America | 2 | 380 086 | 0 | 0 | 0 | 0 |
| Australia | 1 | 31 906 | 0 | 0 | 0 | 0 |
| Asia | 37 | 19 408 954 | 6 | 7717 | 0 | 0 |
| Africa | 10 | 5538 | 1 | 271 | 0 | 0 |
| Study design | ||||||
| Cohort study | 58 | 20 122 822 | 11 | 18 800 | 7 | 16 611 |
| Cross-sectional study | 5 | 2971 | 0 | 0 | 0 | 0 |
| Case-control study | 18 | 191 494 | 6 | 7854 | 0 | 0 |
| Institutional setting | ||||||
| Monocenter | 63 | 467 293 | 16 | 26 339 | 6 | 14 660 |
| Multicenter | 18 | 19 849 994 | 1 | 315 | 1 | 1951 |
| Reported outcomes | ||||||
| Overall PPH cases | 70 | 94 089 of 1 276 153 | 14 | 3746 of 24 541 | 6 | 14 328 of 14 660 |
| Severe PPH cases | 23 | 205 096 of 19 227 091 | 7 | 1167 of 9570 | 4 | 2283 of 9199 |
| Mode of delivery | ||||||
| Vaginal deliveries | 69 | 10 934 443 of 20 214 580 | 15 | 21 417 of 24 856 | 7 | 16 371 of 16 611 |
| Vaginal deliveries only | 20 | 54 404 | 8 | 15 838 | 5 | 14 451 |
| C-sections | 59 | 9 283 280 of 20 249 217 | 9 | 5862 of 10 816 | 2 | 240 of 2160 |
| C-sections only | 9 | 88 841 | 2 | 1798 | 0 | 0 |
| Elective C-sections only | 3 | 2399 | 1 | 129 | 0 | 0 |
| Emergency C-sections only | 3 | 636 | 0 | 0 | 0 | 0 |
| Unknown | 2 | 2259 | 0 | 0 | 0 | 0 |
| Specific population | ||||||
| Singleton pregnancies only | 35 | 958 746 | 9 | 14 622 | 4 | 11 709 |
| Gemellar pregnancies only | 2 | 2166 | 1 | 1085 | 0 | 0 |
| Term deliveries only | 16 | 24 172 | 8 | 12 990 | 4 | 11 709 |
| Type of investigated biomarkers | ||||||
| Hemoglobin | 55 | 20 155 001 | 9 | 18 224 | 4 | 9651 |
| Platelets | 33 | 223 601 | 11 | 13 597 | 5 | 10 199 |
| Fibrinogen | 14 | 17 741 | 9 | 8428 | 6 | 10 600 |
| PT | 10 | 7823 | 7 | 5824 | 3 | 3640 |
| aPTT | 8 | 5449 | 6 | 4792 | 3 | 3640 |
| D-dimers | 4 | 5394 | 2 | 3774 | 1 | 2742 |
| Factor XIII | 3 | 2163 | 2 | 863 | 2 | 863 |
| Antithrombin | 2 | 1161 | 2 | 1161 | 0 | 0 |
| Studies included in qualitative synthesis . | Studies included in overall quantitative synthesis . | Studies using the WHO's definition for PPH and severe PPH included in quantitative synthesis . | ||||
|---|---|---|---|---|---|---|
| . | Number of studies . | Number of pregnant women . | Number of studies . | Number of pregnant women . | Number of studies . | Number of pregnant women . |
| Total | 81 | 20 317 287 | 17 | 26 654 | 7 | 16 611 |
| Study location | ||||||
| Europe | 21 | 219 215 | 8 | 15 772 | 7 | 16 611 |
| North America | 10 | 271 588 | 2 | 2894 | 0 | 0 |
| South America | 2 | 380 086 | 0 | 0 | 0 | 0 |
| Australia | 1 | 31 906 | 0 | 0 | 0 | 0 |
| Asia | 37 | 19 408 954 | 6 | 7717 | 0 | 0 |
| Africa | 10 | 5538 | 1 | 271 | 0 | 0 |
| Study design | ||||||
| Cohort study | 58 | 20 122 822 | 11 | 18 800 | 7 | 16 611 |
| Cross-sectional study | 5 | 2971 | 0 | 0 | 0 | 0 |
| Case-control study | 18 | 191 494 | 6 | 7854 | 0 | 0 |
| Institutional setting | ||||||
| Monocenter | 63 | 467 293 | 16 | 26 339 | 6 | 14 660 |
| Multicenter | 18 | 19 849 994 | 1 | 315 | 1 | 1951 |
| Reported outcomes | ||||||
| Overall PPH cases | 70 | 94 089 of 1 276 153 | 14 | 3746 of 24 541 | 6 | 14 328 of 14 660 |
| Severe PPH cases | 23 | 205 096 of 19 227 091 | 7 | 1167 of 9570 | 4 | 2283 of 9199 |
| Mode of delivery | ||||||
| Vaginal deliveries | 69 | 10 934 443 of 20 214 580 | 15 | 21 417 of 24 856 | 7 | 16 371 of 16 611 |
| Vaginal deliveries only | 20 | 54 404 | 8 | 15 838 | 5 | 14 451 |
| C-sections | 59 | 9 283 280 of 20 249 217 | 9 | 5862 of 10 816 | 2 | 240 of 2160 |
| C-sections only | 9 | 88 841 | 2 | 1798 | 0 | 0 |
| Elective C-sections only | 3 | 2399 | 1 | 129 | 0 | 0 |
| Emergency C-sections only | 3 | 636 | 0 | 0 | 0 | 0 |
| Unknown | 2 | 2259 | 0 | 0 | 0 | 0 |
| Specific population | ||||||
| Singleton pregnancies only | 35 | 958 746 | 9 | 14 622 | 4 | 11 709 |
| Gemellar pregnancies only | 2 | 2166 | 1 | 1085 | 0 | 0 |
| Term deliveries only | 16 | 24 172 | 8 | 12 990 | 4 | 11 709 |
| Type of investigated biomarkers | ||||||
| Hemoglobin | 55 | 20 155 001 | 9 | 18 224 | 4 | 9651 |
| Platelets | 33 | 223 601 | 11 | 13 597 | 5 | 10 199 |
| Fibrinogen | 14 | 17 741 | 9 | 8428 | 6 | 10 600 |
| PT | 10 | 7823 | 7 | 5824 | 3 | 3640 |
| aPTT | 8 | 5449 | 6 | 4792 | 3 | 3640 |
| D-dimers | 4 | 5394 | 2 | 3774 | 1 | 2742 |
| Factor XIII | 3 | 2163 | 2 | 863 | 2 | 863 |
| Antithrombin | 2 | 1161 | 2 | 1161 | 0 | 0 |