Table 1.
Maternal and pregnancy characteristics of women in primary midwifery care at 28 weeks and beyond
| National | Caseload practices | Matched controls | p-value (caseload vs matched) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n = 127,818 | n = 657 | n = 1954 | |||||||
| Maternal age | na | a | |||||||
| Mean | 30.4 | (SD 4.6) | 31.6 | (SD 4.5) | 31.4 | (SD 4.4) | |||
| < 25 | 13,197 | (10.3%) | 32 | (4.9%) | 99 | (5.1%) | |||
| 25–29 | 41,138 | (32.2%) | 192 | (29.2%) | 567 | (29.0%) | |||
| 30–34 | 49,438 | (38.7%) | 272 | (41.4%) | 814 | (41.7%) | |||
| 35–39 | 20,885 | (16.3%) | 132 | (20.1%) | 393 | (20.1%) | |||
| ≥40 | 3160 | (2.5%) | 29 | (4.4%) | 81 | (4.1%) | |||
| Parity | na | a | |||||||
| (missing: 2) | 0 | 58,608 | (45.8%) | 319 | (48.6%) | 940 | (48.1%) | ||
| 1 | 46,010 | (36.0%) | 240 | (36.5%) | 722 | (36.9%) | |||
| ≥2 | 23,198 | (18.1%) | 98 | (14.9%) | 292 | (14.9%) | |||
| Background | na | a | |||||||
| Dutch | 96,589 | (75.6%) | 522 | (79.5%) | 1555 | (79.6%) | |||
| Non Dutch | 31,229 | (24.4%) | 135 | (20.5%) | 399 | (20.4%) | |||
| SES | 0.019 | b | |||||||
| (missing 574) | 1 (low) | 41,146 | (32.3%) | 237 | (36.7%) | 757 | (39.0%) | ||
| 2 (intermediate) | 55,949 | (44.0%) | 248 | (38.4%) | 802 | (41.4%) | |||
| 3 (high) | 30,149 | (23.7%) | 160 | (24.8%) | 380 | (19.6%) | |||
| Urbanisation | < 0.001 | b | |||||||
| (missing 206) | Very urban | 31,693 | (24.8%) | 184 | (28.1%) | 539 | (27.6%) | ||
| Urban | 32,707 | (25.6%) | 193 | (29.5%) | 360 | (18.4%) | |||
| Semi-urban | 23,989 | (18.8%) | 65 | (9.9%) | 253 | (13.0%) | |||
| Rural | 21,991 | (17.2%) | 93 | (14.2%) | 467 | (23.9%) | |||
| Very Rural | 17,232 | (13.5%) | 119 | (18.2%) | 333 | (17.1%) | |||
| Gestational age at intake in practice | < 0.001 | b | |||||||
| (missing 1206) | ≤12 | 112,767 | (89.1%) | 480 | (73.2%) | 1770 | (90.6%) | ||
| 13–27 | 10,578 | (8.4%) | 101 | (15.4%) | 131 | (6.7%) | |||
| 28–36 | 2763 | (2.2%) | 57 | (8.7%) | 37 | (1.9%) | |||
| ≥37 wk | 506 | (0.4%) | 18 | (2.7%) | 3 | (0.2%) | |||
| Antenatally planned place of birth | < 0.001 | b | |||||||
| (missing 3269) | home | 27,111 | (21.8%) | 291 | (44.5%) | 387 | (20.3%) | ||
| birthcentre | 12,666 | (10.2%) | 28 | (4.3%) | 87 | (4.6%) | |||
| hospital | 70,322 | (56.5%) | 272 | (41.6%) | 1177 | (61.6%) | |||
| undecided | 14,450 | (11.6%) | 63 | (9.6%) | 259 | (13.6%) | |||
| Gestational age at birth in weeks | < 0.001 | b | |||||||
| (missing 1432) | < 370 | 5121 | (4.1%) | 20 | (3.1%) | 80 | (4.1%) | ||
| 37–416 | 119,429 | (94.5%) | 601 | (91.8%) | 1829 | (94.2%) | |||
| ≥420 | 1836 | (1.5%) | 34 | (5.2%) | 32 | (1.6%) | |||
| Mean | 39.3 | (SD 1.5) | 39.5 | (SD 1.6) | 39.3 | (SD 1.5) | 0.004 | c | |
| Birthweight (gram) | |||||||||
| (missing 796) | Mean | 3469 | (SD 513) | 3.495 | (SD 499) | 3.475 | (SD 508) | 0.382 | c |
| SGA (<p5) | 4575 | (3.6%) | 26 | (4.0%) | 61 | (3.1%) | 0.302 | b | |
| LGA (>p95) | 5765 | (4.5%) | 26 | (4.0%) | 82 | (4.2%) | 0.790 | b | |
| Birthweight Categories | 0.424 | b | |||||||
| < 2500 | 4267 | (3.3%) | 12 | (1.8%) | 52 | (2.7%) | |||
| 2500–4500 | 120,844 | (94.7%) | 630 | (96.0%) | 1863 | (95.3%) | |||
| > 4500 | 2459 | (1.9%) | 14 | (2.1%) | 35 | (1.8%) | |||
| Multiple pregnancy | 135 | (0.1%) | 1 | (0.2%) | 3 | (0.2%) | |||
| Non-vertex presentation at birth | breech | 3881 | (3.0%) | 15 | (2.3%) | 58 | (3.0%) | ||
| other / unknown | 2746 | (2.1%) | 8 | (1.2%) | 42 | (2.1%) | |||
anot applicable, matching variable
bChi Square
cTwo-sided t-test