Multivariate risk factor analysis for postpartum haemorrhage (PPH) within subgroups
| Characteristics | PPH | UA-PPH | PF-PPH | CT-PPH | CA-PPH |
| General view | |||||
| Age (years) | * | * | – | – | – |
| Ethnicity | ** | ** | ** | * | – |
| Educational attainment | – | – | – | – | – |
| Occupation | ** | ** | ** | – | * |
| Family per capita monthly income (10 000 yuan) | – | – | – | – | – |
| Prepregnancy BMI (kg/m2) | ** | ** | ** | ** | * |
| Smoking | – | – | – | – | * |
| Alcohol consumption | – | – | – | – | – |
| Obstetric and gynaecological history | |||||
| Pregnancy history | – | – | – | – | – |
| Parity (number of deliveries) | ** | ** | ** | * | * |
| History of miscarriage | – | – | – | – | – |
| Spontaneous abortion | – | – | – | – | – |
| Induced abortion or medication abortion | – | – | – | – | – |
| Induced labour | – | – | – | – | – |
| Assisted reproductive technology | – | – | – | – | – |
| Gestational age at delivery (weeks) | ** | ** | * | – | – |
| Diabetes | ** | ** | ** | * | – |
| Hypertension | ** | ** | ** | * | – |
| Anaemia | ** | ** | ** | ** | * |
| Coagulation disorder | ** | – | – | – | * |
| Uterine fibroids/adenomyosis | ** | ** | ** | * | – |
| Polyhydramnios | ** | ** | * | – | – |
| Umbilical cord entanglement | – | – | – | – | – |
| Premature rupture of membranes | ** | ** | ** | * | ** |
| Placental abruption | ** | ** | – | – | – |
| Vaginal bleeding during pregnancy | – | – | – | – | – |
| Scarred uterus | ** | ** | – | – | * |
| Delivery process and neonatal conditions | |||||
| Time of delivery | – | – | – | – | – |
| Total duration of labour | ** | * | * | * | ** |
| First stage of labour—latent phase | ** | ** | – | – | – |
| First stage of labour—lctive phase | ** | ** | – | – | – |
| Second stage of labour | ** | ** | * | ** | – |
| Third stage of labour | ** | – | ** | * | – |
| Placental retention/placenta accreta/placental implantation | ** | ** | ** | ** | ** |
| Analgesia during labour | ** | ** | – | * | ** |
| Instrumental assistance in delivery | ** | – | – | ** | – |
| Lacerations of the cervix, vagina or perineum | ** | – | – | – | |
| Newborn weight (g) | ** | ** | – | – | – |
| Newborn length (cm) | – | – | – | – | – |
*p<0.05; **p<0.001.