Table 1. Maternal characteristics and delivery outcomes for cases of shoulder dystocia compared to the rest of the cohort.
| Shoulder dystocia (n = 6) | No shoulder dystocia (n = 220) | p | |
|---|---|---|---|
| Age (years) | 34.8 (4.5) | 30.3 (3.7) | 0.003 |
| Booking BMI (kg/m 2 ) | 27.4 [25.1–28.8] | 23.3 [21.2–26.8] | 0.02 |
| Current smoking | 1 (16.7%) | 3 (1.4%) | 0.10 |
| Preeclampsia | 1 (16.7%) | 11 (5.0%) | 0.28 |
| Gestational diabetes | 1 (16.7%) | 20 (9.1%) | 0.45 |
| 28–36 week EFW velocity | 22.6 (23.2) | -8.0 (21.0) | 0.0005 |
| 28–36 week AC velocity | 29.6 (16.8) | -0.7 (23.3) | 0.002 |
| Accelerated 28–36 week EFW velocity | 2 (33.3%) | 10 (4.5%) | 0.03 |
| Accelerated 28–36 week AC velocity | 3 (50.0%) | 23 (10.5%) | 0.02 |
| Induction of labour | 4 (66.7%) | 109 (49.5%) | 0.68 |
| Instrumental delivery | 5 (83.3%) | 100 (45.5%) | 0.10 |
| Birthweight (g) | 3507 (460) | 3292 (421) | 0.22 |
| Birthweight centile | 54.3 [35.1–61.4] | 34.6 [16.3–58.3] | 0.14 |
| Birthweight >4000g | 1 (16.7%) | 14 (6.4%) | 0.34 |
| Gestation at birth (weeks) | 40.0 [39.0–41.0] | 40.0 [39.0–40.6] | 0.75 |
The cohort summarised in Table 1 includes all women who delivered their infants vaginally, and where the EFW was ≤95th centile at 36-week ultrasound. Data presented as mean (standard deviation) if normally distributed, as median [interquartile range] if not normally distributed, and as number (%) if categorical. AC = Abdominal circumference; BMI = Body Mass Index; EFW = Estimated fetal weight. “Accelerated 28–36 week velocities” refers to fetuses that demonstrated an increase in EFW or AC of more than 30 centiles between their 28 and 36 week ultrasound scans, standardised over exactly 8 weeks.