Table 2.
Risk pathways for PPH ≥ 500 ml according to chronological variables grouped as prepregnancy, during pregnancy, labour and birth
| Risk factors included in final model | Pre-Pregnancy Variable subgroups 1–4 (1895 women included) OR (95% CI), p | During Pregnancy Variable subgroups 1–10 (1868 women included; 27 excluded due to 1 missing data and 26 perfectly predicted) OR (95% CI), p | Labour and Birth Variable subgroups 1–16 (1724 women included; 171 excluded due to 135 missing data, 36 perfectly predicted) OR (95% CI), p |
|---|---|---|---|
| (1) Sociodemographic | |||
| Age, for each 10 years | 1.45 (1.19–1.76), 0.000 | 1.44 (1.18–1.75), 0.000 | 0.93 (0.73–1.19), 0.57 |
| Black African | 1.77 (1.31–2.39), 0.000 | 1.77 (1.30–2.41), 0.000 | 1.94 (1.35–2.79), 0.000 |
| (2) Local Deprivation: index of multiple deprivation, most deprived UK quintile (%) | |||
| Barriers – housing and services | 1.06 (0.87–1.33), 0.61 | 1.05 (0.83–1.32), 0.69 | 1.04 (0.79–1.36), 0.80 |
| Education, skills and training | 0.93 (0.64–1.36), 0.72 | 0.93 (0.64–1.36), 0.71 | 1.03 (0.57–1.62), 0.89 |
| (3) General and medical risk factors | |||
| Current smoker | 0.76 (0.54–1.09), 0.14 | 0.77 (0.53–1.10), 0.15 | 0.82 (0.53–1.28), 0.38 |
| BMI (kg/m2) per unit | 1.03 (1.01–1.05), 0.006 | 1.03 (1.00–1.05), 0.016 | 1.01 (0.99–1.04), 0.32 |
| Assisted conception | 2.93 (1.30–6.59), 0.010 | 2.28 (0.99–5.29), 0.054 | 2.10 (0.83–5.33), 0.19 |
| (4) Previous obstetric history | |||
| Previous PPH | 2.34 (1.33–4.12), 0.003 | 2.45 (1.38–4.35), 0.002 | 2.75 (1.40–5.44), 0.003 |
| Multiparous previous caesarean | 1.32 (0.93–1.87), 0.19 | 1.30 (0.91–1.86), 0.14 | 0.96 (0.61–1.51), 0.86 |
| Multiparous no previous caesarean | 0.33 (0.26–0.42), 0.000 | 0.33 (0.25–0.42), 0.000 | 0.79 (0.56–1.11), 0.18 |
| (5) Current pregnancy | |||
| Multiple pregnancy | 2.27 (1.04–4.96), 0.039 | 2.02 (0.82–5.00), 0.13 | |
| Admissions >24 weeks | 0.82 (0.57–1.18), 0.28 | 0.82 (0.53–1.29), 0.39 | |
| (6) Antenatal day unit (ADU) attendances | |||
| Any ADU attendance | 1.06 (0.84–1.34), 0.62 | 0.95 (0.72–1.26), 0.74 | |
| Pre-eclampsia screen | 1.06 (0.65–1.75), 0.81 | 1.04 (0.57–1.91), 0.89 | |
| Generally unwell | 1.22 (0.68–2.18), 0.50 | 1.33 (0.69–2.60), 0.40 | |
| (7) Placenta praevia: All 26 women with major or anterior placenta praevia PPH > 500 ml | |||
| (8) Antepartum haemorrhage (APH) and urinary tract infection | |||
| APH | 1.11 (0.62–1.99), 0.74 | 1.27 (0.65–2.51), 0.48 | |
| ‘Warning APH’ | 8.95 (1.02–78.7), 0.048 | 1.92 (0.19–19.3), 0.58 | |
| (9) Pre-eclampsia (PET) and anaemia | |||
| Gestational hypertension | 1.83 (0.83–4.03), 0.13 | 2.22 (0.87–5.63), 0.093 | |
| Pre-eclampsia | 3.16 (1.12–8.93), 0.030 | 3.21 (0.94–10.90), 0.062 | |
| (10) Medications in pregnancy pre-birth | |||
| Antibiotics | 1.35 (1.01–1.80), 0.043 | 1.14 (0.77–1.66), 0.52 | |
| Antihypertensives (including for PET) | 0.75 (0.44–1.29), 0.30 | 0.66 (0.33–1.32), 0.24 | |
| Diabetic Rx | 1.89 (0.79–4.56), 0.15 | 1.20 (0.43–3.37), 0.73 | |
| Steroids for fetal reasons | 0.90 (0.57–1.43), 0.65 | 1.23 (0.69–2.18), 0.49 | |
| (11) Gestation at birth | |||
| Gestation at delivery (weeks) | 0.98 (0.90–1.08), 0.70 | ||
| (12) Birthweight | |||
| Maximum birthweight (kg) | 2.19 (1.62–2.99), 0.000 | ||
| (13) Onset of labour | |||
| No labour onset | 1.51 (0.47–4.90), 0.49 | ||
| Induction | 0.75 (0.39–1.46), 0.40 | ||
| Augmentation | 0.83 (0.42–1.64), 0.59 | ||
| ROM > 2 hours before onset | 0.95 (0.64–1.41), 0.79 | ||
| ROM > 6 hours before onset | 1.35 (0.90–2.02), 0.14 | ||
| ROM not recorded | 1.03 (0.60–1.77), 0.91 | ||
| (14) Intrapartum: all ten women with evidence of chorioamnionitis PPH > 500 ml | |||
| Prostin | 1.04 (0.53–2.02), 0.91 | ||
| Syntocinon® | 1.44 (0.95–2.16), 0.085 | ||
| Spinal anaesthesia | 0.87 (0.51–1.49), 0.60 | ||
| Epidural analgesia | 1.08 (0.71–1.65), 0.71 | ||
| Raised temperature (per degree >37.0°C) | 2.62 (1.24–5.52), 0.011 | ||
| Temperature not recorded | 0.75 (0.50–1.11), 0.15 | ||
| (15) Birth | |||
| Instrumental vaginal | 3.50 (2.21–5.24), 0.000 | ||
| Elective caesarean | 24.4 (5.53–108.00), 0.000 | ||
| Emergency caesarean section | 40.5 (16.30–101.00), 0.000 | ||
| (16) Third stage | |||
| Physiological | 1.48 (0.80–2.77), 0.22 | ||
| Syntometrine® intramuscular | 0.55 (0.33–0.91), 0.019 | ||
| Syntocinon® intravenous bolus | 0.58 (0.27–1.25), 0.17 | ||
| Syntocinon® 40/50 IU infusion commenced | 0.61 (0.38 –0.99), 0.045 | ||
| Retained placenta | 21.3 (8.31–54.70), 0.000 | ||
| Suture interval after vaginal birth (hours) | 2.03 (1.65–2.50), 0.000 | ||
| Suture interval not recorded | 2.2 (1.32–3.69), 0.003 | ||
Full regression model; result of three multiple regression models selecting the principal significant variables. In each model, an additional group of predictors is added. Results adjusted for other members of the same group and for previous groups only.