Procedural factors in relation to time of operative vaginal delivery
| Daytime 08:00–19:59 n=301 (%) | Night-time 20:00–07:59 n=296 (%) | OR (95% CI) | |
|---|---|---|---|
| Vacuum—primary instrument | 195 (64.8) | 213 (72.0) | 0.72 (0.51 to 1.01) |
| Forceps—primary instrument | 95 (31.6) | 79 (26.7) | 1.27 (0.89 to 1.81) |
| Sequential use of instruments | 28 (9.3) | 38 (12.8) | 0.70 (0.42 to 1.17) |
| More than 3 pulls with instrument (s) | 21 (7.0) | 13 (4.4) | 1.63 (0.80 to 3.33) |
| Junior operator (SHO/junior registrar) | 69 (22.9) | 52 (17.6) | 1.40 (0.93 to 2.09) |
| Mid-grade operator (registrar year 1–3) | 114 (37.9) | 149 (50.4) | 0.60 (0.43 to 0.83)* |
| Senior operator (registrar year 4–5+) | 48 (15.9) | 35 (11.8) | 1.42 (0.89 to 2.26) |
| Consultant operator | 70 (23.3) | 60 (20.3) | 1.19 (0.81 to 1.76) |
| Second operator involved | 22 (7.3) | 8 (2.7) | 2.84 (1.24 to 6.48)* |
| Consultant supervisor present | 22 (7.3) | 10 (3.4) | 2.26 (1.05 to 4.85)* |
| Consultant called after complication | 5 (1.7) | 3 (1.0) | 1.65 (0.39 to 7.00) |
| Transfer to theatre | 26 (8.6) | 37 (12.5) | 0.66 (0.39 to 1.12) |
| Caesarean section assessed for OVD | 12 (4.0) | 10 (3.3) | 1.19 (0.51 to 2.79) |
| Caesarean section after failed instrumental | 2 (0.7) | 6 (2.0) | 0.32 (0.07 to 1.62) |
| Caesarean no attempt at instrumental | 10 (3.3) | 4 (1.3) | 2.51 (0.78 to 8.09) |
| Mean DDI in minutes (SD)† | 12.0 (8.1) | 12.6 (8.7) | −0.6 (−0.3 to 1.1) |
*p<0.05.
†DDI—the time between the decision to intervene to the delivery of the infant; difference in means.
DDI, decision to delivery interval; OVD, operative vaginal delivery; SHO, senior house officer.