Table 3. Association between the risk factors and postpartum hemorrhage.
| Variable | No PPH n = 975 (%) | PPH n = 93 (%) | P value | |
|---|---|---|---|---|
| Age at birth | ||||
| under 19 | 51 (5.2) | 3 (3.2) | <0.05 | |
| 20–35 | 652 (66.9) | 62 (66.7) | Reference | |
| 35–40 | 228 (23.4) | 21 (22.6) | NS | |
| over 40 | 44 (4.5) | 7 (7.5) | <0.05 | |
| Pre-pregnant body mass index | ||||
| under 18.4 | 173 (17.7) | 18 (19.4) | NS | |
| 18.5–24.9 | 661 (67.8) | 59 (63.4) | Reference | |
| over 25.0 | 141 (14.5) | 16 (17.2) | NS | |
| Parity | ||||
| Primipara | 485 (49.7) | 44 (47.3) | Reference | |
| Multipara | 490 (50.3) | 49 (52.7) | NS | |
| Artificial reproductive technique | ||||
| No | 945 (96.9) | 84 (90.3) | Reference | |
| Yes | 30 (3.1) | 9 (9.7) | <0.01 | |
| Smoking habit | ||||
| No | 911 (93.4) | 86 (92.5) | Reference | |
| Yes | 64 (6.6) | 7 (7.5) | NS | |
| Weight gain during pregnancy (Kg) | ||||
| less 9.9 | 552 (56.6) | 36 (38.7) | Reference | |
| 10.0–14.9 | 337 (34.6) | 40 (43.0) | NS | |
| over 15.0 | 86 (8.8) | 17 (18.3) | <0.01 | |
| Gestational week at delivery (weeks) | ||||
| after 40/0 | 283 (29.0) | 31 (33.3) | NS | |
| 37/0-39/6 | 549 (56.3) | 56 (60.2) | Reference | |
| before 36/6 | 143 (14.7) | 6 (6.5) | <0.01 | |
| Pregnancy induced hypertension | ||||
| No | 913 (93.6) | 78 (83.9) | Reference | |
| Yes | 62 (6.4) | 15 (16.1) | <0.01 | |
| Labor induction/ augmentation by oxytocin | ||||
| No | 657 (67.4) | 60 (64.5) | Reference | |
| Yes | 318 (32.6) | 33 (35.5) | NS | |
| Assisted vaginal delivery | ||||
| No | 897 (92.0) | 84 (90.3) | Reference | |
| Yes | 78 (8.0) | 9 (9.7) | NS | |
| Severe vaginal/perineal laceration | ||||
| No | 834 (85.5) | 68 (73.1) | Reference | |
| Yes | 141 (14.5) | 25 (26.9) | <0.01 | |
| Neonatal birth weight (g) | ||||
| less 2499 | 209 (21.4) | 2 (2.2) | <0.01 | |
| 2500–3499 | 679 (69.6) | 67 (72.0) | Reference | |
| 3500–3999 | 77 (7.9) | 20 (21.5) | <0.05 | |
| over 4000 | 10 (1.0) | 4 (4.3) | <0.01 | |