Table 3.
Intrapartum interventions and adverse maternal outcomes by maternal age in low-risk nulliparous women aged 16 and over
| OU |
Non-OU |
|||||
|---|---|---|---|---|---|---|
| Events/births | Weighted* |
Events/births | Weighted* |
|||
| Age (years) | n/N | % | (95% CI) | n/N | % | (95% CI) |
| Maternal composite | ||||||
| 16–19 | 480/1239 | 39.4 | (35.6 to 43.3) | 252/1553 | 17.5 | (15.2 to 20.1) |
| 20–24 | 1229/2577 | 47.9 | (44.7 to 51.1) | 886/3679 | 24.2 | (21.8 to 26.8) |
| 25–29 | 1670/3003 | 55.6 | (53.4 to 57.9) | 1680/5354 | 32.3 | (29.5 to 35.2) |
| 30–34 | 1402/2322 | 61.1 | (57.3 to 64.8) | 1730/4897 | 36.6 | (34.2 to 39.1) |
| 35–39 | 622/957 | 65.5 | (61.8 to 69.1) | 792/1995 | 39.9 | (36.0 to 43.9) |
| 40+ | 108/148 | 71.9 | (63.0 to 79.3) | 83/196 | 44.8 | (35.2 to 54.7) |
| Total | 5511/10 246 | 54.4 | (51.9 to 56.9) | 5423/17 674 | 31.3 | (29.3 to 33.4) |
| Augmentation | ||||||
| 16–19 | 317/1245 | 25.9 | (22.5 to 29.7) | 141/1564 | 8.6 | (7.0 to 10.5) |
| 20–24 | 790/2584 | 30.7 | (26.9 to 34.7) | 489/3706 | 12.9 | (11.1 to 14.9) |
| 25–29 | 1079/3011 | 35.7 | (33.4 to 38.1) | 918/5372 | 17.4 | (15.6 to 19.3) |
| 30–34 | 867/2318 | 37.5 | (34.1 to 41.1) | 964/4921 | 19.9 | (18.3 to 21.7) |
| 35–39 | 402/955 | 42.2 | (36.4 to 48.1) | 473/2015 | 22.6 | (19.8 to 25.7) |
| 40+ | 71/149 | 47.6 | (37.0 to 58.4) | 44/196 | 23.7 | (15.7 to 34.1) |
| Total | 3526/10 262 | 34.6 | (31.9 to 37.4) | 3029/17 774 | 16.9 | (15.7 to 18.1) |
| Instrumental delivery | ||||||
| 16–19 | 191/1266 | 15.1 | (12.5 to 18.2) | 99/1568 | 7.9 | (6.2 to 10.2) |
| 20–24 | 469/2618 | 17.9 | (15.9 to 20.0) | 392/3717 | 10.6 | (8.9 to 12.5) |
| 25–29 | 707/3039 | 23.4 | (21.3 to 25.6) | 772/5391 | 15.0 | (13.1 to 17.0) |
| 30–34 | 591/2349 | 26.3 | (21.3 to 32.1) | 795/4950 | 17.0 | (15.2 to 19.1) |
| 35–39 | 275/968 | 29.5 | (25.0 to 34.4) | 401/2018 | 19.4 | (15.9 to 23.6) |
| 40+ | 41/149 | 30.4 | (20.0 to 43.2) | 37/197 | 21.0 | (13.3 to 31.5) |
| Total | 2274/10 389 | 22.5 | (19.9 to 25.3) | 2496/17 841 | 14.5 | (13.0 to 16.0) |
| Intrapartum caesarean section | ||||||
| 16–19 | 101/1266 | 8.3 | (6.5 to 10.5) | 55/1568 | 3.3 | (2.5 to 4.2) |
| 20–24 | 313/2618 | 12.2 | (10.4 to 14.2) | 194/3717 | 5.2 | (4.2 to 6.5) |
| 25–29 | 461/3039 | 15.2 | (13.3 to 17.2) | 408/5391 | 8.0 | (6.9 to 9.3) |
| 30–34 | 466/2349 | 19.8 | (17.5 to 22.3) | 452/4950 | 9.0 | (7.9 to 10.4) |
| 35–39 | 223/968 | 23.0 | (19.8 to 26.5) | 212/2018 | 11.2 | (9.0 to 13.9) |
| 40+ | 47/149 | 29.2 | (20.9 to 39.3) | 22/197 | 9.7 | (5.2 to 17.2) |
| Total | 1611/10 389 | 15.7 | (14.1 to 17.5) | 1343/17 841 | 7.6 | (6.8 to 8.4) |
*Percentages are weighted to take account of differences in the probability of a woman being selected for inclusion in the study arising from differences in each unit/trust's period of participation and the stratum-specific probabilities of selection of OUs.
OU, obstetric unit.