Table 1.
Characteristics of the study population
| Population | IOL at 40 GW (40 + 0 to 40 + 6) N = 456 n (%) |
IOL at 41 GW (41 + 0 to 41 + 6) N = 318 n (%) |
SOL (40 + 0 to 41 + 6) N = 1585 n (%) |
|---|---|---|---|
| Maternal Age | |||
| < 35 years | 401 (87.9) | 290 (91.2) | 1424 (89.8) |
| ≥ 35 years | 55 (12.1) | 28 (8.8) | 161 (10.2) |
| Education | |||
| None | 1 (0.2) | 2 (0.6) | 2 (0.1) |
| Primary | 10 (2.2) | 4 (1.3) | 26 (1.6) |
| Secondary | 353 (77.4) a | 266 (83.6) | 1341 (84.6) |
| Higher | 91 (20.0) a | 46 (14.5) | 211 (13.3) |
| Missing | 1 (0.2) | 0 | 5 (0.4) |
| Working status | |||
| Working | 81 (17.8) | 48 (15.1) | 227 (14.3) |
| Housewife | 370 (81.1) | 270 (84.9) | 1344 (84.8) |
| Missing | 5 (1.1) | 0 | 14 (0.9) |
| Marital status | |||
| Married | 451 (98.9) | 311 (97.8) | 1570 (98.6) |
| Unmarried | 3 (0.7) | 7 (2.2) b | 14 (0.9) |
| Unmarried living together | 1 (0.2) | 0 | 2 (0.1) |
| Missing | 1 (0.2) | 0 | 6 (0.4) |
| Parity | |||
| 0 | 260 (57.0) a | 198 (62.3) b | 754 (47.6) |
| ≥ 1 | 196 (43.0) a | 120 (37.7) b | 831 (52.4) |
| Asian criteria-based BMI [25] | |||
| Underweight (< 18.4) | 38 (8.3) | 33 (10.4) | 159 (10.0) |
| Normal (18.5–22.9) | 312 (68.4) | 190 (59.7) b | 1061 (67.0) |
| Overweight (23–27.4) | 106 (23.2) | 95 (29.9) b | 365 (23.0) |
| Operator delivering care | |||
| Nurse | 200 (43.9) a | 116 (36.5) b | 899 (56.7) |
| Midwife | 110 (24.1) | 101 (31.8) | 431 (27.2) |
| House Officer | 4 (0.9) | 4 (1.3) | 24 (1.5) |
| Mid-level staff c | 140 (30.7) a | 96 (30.2) b | 224 (14.1) |
| Consultant | 2 (0.4) | 1 (0.3) | 3 (0.2) |
| Missing | 0 | 0 | 4 (0.3) |
| Neonatal weight at birth | |||
| 2000 | 0 | 0 | 0 |
| 2000 to 2499 | 13 (2.9) | 3 (0.9) b | 55 (3.5) |
| 2500 to 3499 | 374 (82.0) | 246 (77.4) | 1278 (80.6) |
| 3500 to 4000 | 57 (12.5) | 61 (19.2) b | 234 (14.8) |
| > 4000 | 11 (2.4) a | 8 (2.5) b | 13 (0.8) |
| Missing | 1 (0.2) | 0 | 5 (0.3) |
Abbreviations: BMI Body mass index, GW Gestational weeks. IOL Induction of labour, SOL Spontaneous onset of labour
aStatistically significant p value (p < 0.05) in the comparison IOL at 40 GW vs SOL; b Statistically significant p value (p < 0.05) in the comparison IOL at 41 GW vs SOL; c Mid-level staff defined as Senior House Officer or Registrar