Table 2.
Delivery outcomes in intention to treat population. Values are numbers (percentages) unless stated otherwise
| Variables | Induction group (n=1381) | Expectant management group (n=1379) | Relative risk (95% CI) | P value; mean (95% CI) difference between groups |
|---|---|---|---|---|
| Gestational age at delivery (days) | n=1381 | n=1379 | ||
| Mean (SD) | 288.8 (1.3) | 291.7 (2.7) | — | −2.91 (−3.07 to −2.76) |
| Median (interquartile range) | 289 (288-289) | 292 (289-294) | — | — |
| Time from randomisation to delivery (days) | n=1381 | n=1379 | ||
| Mean (SD) | 1.76 (1.42) | 4.66 (2.64) | — | −2.91 (−3.06 to −2.75) |
| Median (interquartile range) | 2 (1-2) | 4 (2-7) | — | — |
| Time from admittance to labour ward to delivery (hours) | n=1380 | n=1378 | ||
| Mean (SD) | 20.1 (14.8) | 13.6 (12.2) | — | <0.001; 6.49 (5.50 to 7.50) |
| Median (interquartile range) | 16.2 (9.2-27.9) | 10.4 (4.6-19.0) | — | — |
| Onset of birth process | ||||
| Spontaneous | 195/1381 (14.1) | 920/1379 (66.7) | — | — |
| Scheduled caesarean delivery | 5/1381 (0.4) | 2/1379 (0.1) | — | — |
| Induction: | 1181/1381 (85.5) | 457/1379 (33.1) | — | — |
| Mode of induction: | — | |||
| Cervical ripening | 905/1181 (76.6) | 340/457 (74.4) | — | — |
| Amniotomy without oxytocin | 130/1181 (11.0) | 45/457 (9.8) | — | — |
| Amniotomy with oxytocin | 146/1181 (12.4) | 72/457 (15.8) | — | 0.18 |
| Cervical ripening: | ||||
| First method mechanical | 343/905 (37.9) | 126/340 (37.1) | — | |
| First method drug | 562/905 (62.1) | 214/340 (62.9) | 0.99 (0.90 to 1.09) | 0.84 |
| Indication for induction | ||||
| Randomisation to 41 weeks and induction according to protocol | 1146/1181 (97.0) | 0 (0.0) | — | — |
| Randomisation to 42 weeks and induction according to protocol | 0/1181 (0.0) | 373/457 (81.6) | — | — |
| Maternal condition | 1/1181 (0.1) | 38/457 (8.3) | — | — |
| Fetal condition | 0 (0.0) | 18/457 (3.9) | — | — |
| Maternal request* | 6/1181 (0.5) | 23/457 (5.0) | — | — |
| Other† | 28/1181 (2.4) | 5/457 (1.1) | — | — |
| Duration of labour (hours) | n=717 | n=880 | ||
| Mean (SD) | 7.13 (5.39) | 8.32 (5.94) | — | <0.001, 1.19 (−1.76 to −0.64) |
| Median (interquartile range) | 5.67 (2.85-10.28) | 6.86 (3.76-11.45) | — | — |
| Use of epidural anaesthesia | 729/1381 (52.8) | 669/1379 (48.5) | 1.09 (1.01 to 1.17) | 0.03 |
| Meconium stained amniotic fluid | 233/1238 (18.8) | 320/1127 (28.4) | 0.66 (0.57 to 0.77) | <0.001 |
| Mode of delivery | ||||
| Non-instrumental vaginal | 1150/1381 (83.3) | 1140/1379 (82.7) | 1.01 (0.97 to 1.04) | 0.71 |
| Caesarean section | 143/1381 (10.4) | 148/1379 (10.7) | 0.96 (0.78 to 1.20) | 0.79 |
| Assisted vaginal | 88/1381 (6.4) | 91/1379 (6.6) | 0.97 (0.73 to 1.28) | 0.87 |
| Emergency caesarean | 138/143 (96.5) | 146/148 (98.6) | 0.98 (0.94 to 1.01) | 0.42 |
| Indication for emergency caesarean | ||||
| Failed induction‡ | 8/138 (5.8) | 7/146 (4.8) | — | — |
| Failure to progress at first stage | 60/138 (43.5) | 53/146 (36.3) | — | — |
| Fetal distress at first stage | 35/138 (25.4) | 28/146 (19.2) | — | — |
| Failure to progress and fetal distress at first stage | 6/138 (4.3) | 7/146 (4.8) | — | — |
| Other indication at first stage | 5/138 (3.6) | 5/146 (3.4) | — | — |
| Failure to progress at second stage | 11/138 (8.0) | 23/146 (15.8) | — | — |
| Fetal distress at second stage | 6/138 (4.3) | 8/146 (5.5) | — | — |
| Failure to progress and fetal distress at second stage | 0 (0.0) | 3/146 (2.1) | — | — |
| Failure of operative vaginal delivery | 7/138 (5.1) | 12/146 (8.2) | — | 0.27 |
| Indication for assisted vaginal delivery | ||||
| Failure to progress | 37/88 (42.0) | 28/91 (30.8) | — | — |
| Fetal distress | 33/88 (37.5) | 34/91 (37.4) | — | — |
| Failure to progress and fetal distress | 5/88 (5.7) | 7/91 (7.7) | — | — |
| Maternal distress | 13/88 (14.8) | 21/91 (23.1) | — | — |
| Other | 0 (0.0) | 1/91 (1.1) | — | 0.35 |
| Duration of hospital stay from delivery to discharge (hours) | n=1333 | n=1333 | ||
| Mean (SD) | 46.3 (27.0) | 47.1 (29.7) | — | 0.46; −0.82 (−2.99 to 1.32) |
| Median (interquartile range) | 43.6 (25.3-61.6) | 44.8 (25.8-61.2) | — | — |
| Breast feeding | ||||
| At discharge from delivery hospital | 987/1019 (96.9) | 981/1014 (96.7) | 1.00 (0.99 to 1.02) | 0.98 |
| 4 weeks after delivery | 835/923 (90.5) | 824/939 (87.8) | 1.03 (1.00 to 1.06) | 0.07 |
*
Maternal request outside study protocol (eg, women in early induction group were induced on request after 41 weeks+1 day and women in expectant management group were induced on request before 42weeks+0 days).
†
Induction outside study protocol because of administrative errors or lack of capacity on labour ward.
‡
Caesarean section performed when active labour was not reached despite different methods for induction of labour being used, usually for at least 48 hours.