Table 4 Trends in clinical outcomes for nulliparous planned vaginal births 2001–2020

IOL

134,156 (36.5%)

11,078 (34.1%)

10,645 (33.5%)

11,351 (33.2%)

12,201 (32.5%)

12,291 (31.6%)

13,116 (33.0%)

14,108 (35.0%)

15,156 (39.1%)

16,736 (45.1%)

17,474 (47.1%)

Spontaneous onset of labour

233,738 (63.5%)

21,384 (65.9%)

21,128 (66.5%)

22,836 (66.8%)

25,363 (67.5%)

26,626 (68.4%)

26,587 (67.0%)

26,218 (65.0%)

23,610 (60.9%)

20,375 (54.9%)

19,611 (52.9%)

Augmentation (n = 233,738 )

119,790 (51.2%)

11,372 (53.2%)

11,383 (53.9%)

11,880 (52.0%)

13,302 (52.4%)

13,356 (50.2%)

12,983 (48.8%)

12,893 (49.2%)

12,144 (51.4%)

10,678 (52.4%)

9,799 (50.0%)

Epidural analgesia

171,602 (46.6%)

12,770 (39.3%)

13,056 (41.1%)

14,471 (42.3%)

16,214 (43.2%)

17,012 (43.7%)

18,040 (45.4%)

19,213 (47.6%)

19,376 (50.0%)

20,207 (54.5%)

21,243 (57.3%)

Mode of birth

 Unassisted vaginal birth

205,203 (55.8%)

20,286 (62.5%)

19,152 (60.3%)

19,963 (58.4%)

21,056 (56.1%)

21,635 (55.6%)

21,713 (54.7%)

22,006 (54.6%)

20,884 (53.9%)

19,263 (51.9%)

19,245 (51.9%)

 Assisted vaginal birth

81,447 (22.1%)

5,800 (17.9%)

5,939 (18.7%)

6,552 (19.2%)

7,890 (21.0%)

8,715 (22.4%)

9,071 (22.8%)

9,599 (23.8%)

9,568 (24.7%)

9,233 (24.9%)

9,080 (24.5%)

 Caesarean section

81,244 (22.1%)

6,376 (19.6%)

6,682 (21.0%)

7,672 (22.4%)

8,618 (22.9%)

8,567 (22.0%)

8,919 (22.5%)

8,721 (21.6%)

8,314 (21.4%)

8,615 (23.2%)

8,760 (23.6%)

Perineal status (n = 286,526)

 Intact

37,338 (13.0%)

5,562 (21.3%)

5,130 (20.4%)

5,195 (19.6%)

4,521 (15.6%)

3,730 (12.3%)

3,678 (12.0%)

3,212 (10.2%)

2,465 (8.1%)

1,942 (6.8%)

1,903 (6.7%)

 1st degree

68,635 (24.0%)

6,824 (26.2%)

6,230 (24.8%)

6,545 (24.7%)

7,647 (26.4%)

8,401 (27.7%)

8,008 (26.0%)

7,406 (23.4%)

6,679 (21.9%)

5,672 (19.9%)

5,223 (18.5%)

 2nd degree

90,533 (31.6%)

7,503 (28.8%)

7,083 (28.2%)

7,783 (29.4%)

9,006 (31.1%)

9,889 (32.6%)

10,029 (32.6%)

10,566 (33.4%)

10,229 (33.6%)

9,215 (32.4%)

9,230 (32.6%)

 3rd /4th degree

11,634 (4.1%)

933 (3.6%)

909 (3.6%)

1,011 (3.8%)

1,285 (4.4%)

1,353 (4.5%)

1,469 (4.8%)

1,422 (4.5%)

1,212 (4.0%)

1,064 (3.7%)

976 (3.4%)

 Episiotomy

78,386 (27.4%)

5,264 (20.2%)

5,739 (22.9%)

5,981 (22.6%)

6,485 (22.4%)

6,959 (22.9%)

7,572 (24.6%)

8,989 (28.5%)

9,845 (32.4%)

10,576 (37.1%)

10,976 (38.8%)

Infant birth weight > 4200 g

18,202 (4.9%)

1,879 (5.8%)

1,751 (5.5%)

1,905 (5.6%)

2,139 (5.7%)

2,083 (5.4%)

2,165 (5.5%)

1,971 (4.9%)

1,633 (4.2%)

1,303 (3.5%)

1,373 (3.7%)