Table 1 Characteristics of the participants
From: Prevalence of amniotomy in Sweden: a nationwide register study
All births n = 330,913 | Robson 1 and 3 n = 219,961 | Robson 1 n = 98,442 | Robson 3 n = 121,519 | |
|---|---|---|---|---|
Age (years), mean (SD) | 30.9 (4.9) | 30.6 (4.8) | 29.0 (4.6) | 31.9 (4.6) |
BMI (kg/m2), mean (SD) | 25.1 (4.9) | 24.6 (4.5) | 24.2 (4.4) | 24.9 (4.7) |
BMI categorization, n (%) | ||||
< 18.5, n (%) | 7967 (2.6) | 5880 (2.9) | 2968 (3.3) | 2912 (2.6) |
18.5–24.9 | 171,406 (55.8) | 121,853 (59.6) | 57,203 (63.0) | 64,650 (56.9) |
25–29.9 | 81,994 (26.7) | 51,804 (25.4) | 21,427 (23.6) | 30,377 (26.8) |
30–34.9 | 31,764 (10.3) | 17,913 (8.8) | 6645 (7.3) | 11,268 (9.9) |
35–39.9 | 10,456 (3.4) | 5213 (2.5) | 1914 (2.1) | 3299 (2.9) |
> 40 | 3715 (1.2) | 1643 (0.8) | 614 (0.7) | 1029 (0.9) |
Unknown | 23,611 | 15,665 | 7671 | 7984 |
Country of origin, n (%) | ||||
Sweden | 215,130 (70.5) | 144,286 (70.9) | 68,089 (75.0) | 76,197 (67.5) |
Born outside Sweden but in the EU | 26,093 (8.6) | 17,871 (8.8) | 7816 (8.6) | 10,055 (8.9) |
Born outside the EU | 63,690 (20.9) | 41,429 (20.3) | 14,860 (16.4) | 26,569 (23.5) |
Unknown | 26,000 | 16,375 | 7677 | 8698 |
Highest level of education, n (%) | ||||
No education or education < 9 years | 17,420 (6.2) | 11,204 (6.0) | 4044 (4.8) | 7160 (6.9) |
Lower secondary school | 7320 (2.6) | 4686 (2.5) | 1008 (1.2) | 3678 (3.6) |
Upper secondary school | 149,834 (53.5) | 101,849 (54.3) | 48,237 (57.1) | 53,612 (52.0) |
University | 105,416 (37.6) | 69,707 (37.2) | 31,124 (36.9) | 38,583 (37.4) |
Unknown | 50,923 | 32,515 | 14,029 | 18,486 |
Multiple pregnancies, n (%) | 4089 (1.2) | – | – | – |
Mode of birth, n (%) | ||||
Spontaneously vaginal | 273,084 (84.8) | 198,420 (90.6) | 80,904 (82.4) | 117,516 (97.2) |
Instrumental | 17,676 (5.5) | 11,183 (5.1) | 9742 (9.9) | 1441 (1.2) |
Emergency cesarean section | 31,166 (9.7) | 9504 (4.3) | 7586 (7.7) | 1918 (1.6) |
Unknown | 8987 | 854 | 210 | 644 |