Table 1.
Characteristics of healthy women with low risk pregnancies by their planned place of birth at start of care in labour. Values are numbers (percentages) of women unless stated otherwise
| Obstetric unit (n=19 706) | Home (n=16 840) | Freestanding midwifery unit (n=11 282) | Alongside midwifery unit (n=16 710) | |
|---|---|---|---|---|
| Maternal age (years): | ||||
| Mean (SD) | 28.2 (6.0) | 31.1 (5.2) | 28.8 (5.8) | 28.3 (5.7) |
| <20 | 1506 (7.7) | 218 (1.3) | 677 (6.0) | 1069 (6.4) |
| 20–24 | 4251 (21.6) | 1706 (10.2) | 2132 (18.9) | 3489 (20.9) |
| 25–29 | 5701 (29.0) | 4346 (25.9) | 3267 (29.0) | 5001 (30.0) |
| 30–34 | 5063 (25.7) | 5848 (34.8) | 3248 (28.8) | 4582 (27.5) |
| 35–39 | 2640 (13.4) | 4017 (23.9) | 1690 (15.0) | 2232 (13.4) |
| ≥40 | 520 (2.6) | 671 (4.0) | 254 (2.3) | 299 (1.8) |
| Missing | 25 | 34 | 14 | 38 |
| Ethnic group: | ||||
| White | 16 068 (81.7) | 15 937 (94.8) | 10 329 (91.6) | 13 485 (80.9) |
| Indian | 477 (2.4) | 67 (0.4) | 87 (0.8) | 509 (3.1) |
| Pakistani | 636 (3.2) | 41 (0.2) | 164 (1.5) | 545 (3.3) |
| Bangladeshi | 297 (1.5) | 14 (0.1) | 147 (1.3) | 130 (0.8) |
| Black Caribbean | 265 (1.3) | 127 (0.8) | 48 (0.4) | 198 (1.2) |
| Black African | 670 (3.4) | 112 (0.7) | 94 (0.8) | 520 (3.1) |
| Mixed | 328 (1.7) | 280 (1.7) | 124 (1.1) | 293 (1.8) |
| Other | 938 (4.8) | 241 (1.4) | 284 (2.5) | 993 (6.0) |
| Missing | 27 | 21 | 5 | 37 |
| Understanding of English: | ||||
| Fluent | 18 044 (92.3) | 16 724 (99.5) | 10 927 (97.1) | 15 196 (91.3) |
| Some | 1130 (5.8) | 75 (0.4) | 273 (2.4) | 1176 (7.1) |
| None | 380 (1.9) | 15 (0.1) | 55 (0.5) | 274 (1.6) |
| Missing | 152 | 26 | 27 | 64 |
| Marital or partner status: | ||||
| Married or living with partner | 17 097 (88.2) | 16 056 (96.0) | 10 444 (93.6) | 15 014 (91.2) |
| Single or unsupported by partner | 2289 (11.8) | 673 (4.0) | 718 (6.4) | 1453 (8.8) |
| Missing | 320 | 111 | 120 | 243 |
| Body mass index in pregnancy: | ||||
| Mean (SD) | 24.4 (4.0) | 24.0 (3.7) | 24.1 (3.7) | 24.0 (3.8) |
| Not recorded in maternity notes | 3566 (18.1) | 3268 (19.5) | 1861 (16.5) | 2927 (17.6) |
| <18.5 | 570 (2.9) | 321 (1.9) | 234 (2.1) | 438 (2.6) |
| 18.5–24.9 | 8856 (45.1) | 8155 (48.7) | 5605 (49.8) | 8218 (49.4) |
| 25.0–29.9 | 4731 (24.1) | 3776 (22.5) | 2653 (23.6) | 3789 (22.8) |
| 30.0–35.0 | 1928 (9.8) | 1226 (7.3) | 912 (8.1) | 1272 (7.6) |
| Missing | 55 | 94 | 17 | 66 |
| Deprivation score (quintile)*: | ||||
| 1st (least deprived) | 3157 (16.1) | 3688 (22.1) | 2496 (22.2) | 2535 (15.2) |
| 2nd | 3618 (18.5) | 3483 (20.8) | 2582 (22.9) | 2648 (15.9) |
| 3rd | 3698 (18.9) | 3650 (21.8) | 2304 (20.5) | 3245 (19.5) |
| 4th | 4084 (20.9) | 3336 (19.9) | 2080 (18.5) | 3852 (23.1) |
| 5th (most deprived) | 5023 (25.7) | 2565 (15.3) | 1789 (15.9) | 4382 (26.3) |
| Missing | 126 | 118 | 31 | 48 |
| Previous pregnancies (≥24 weeks): | ||||
| 0 | 10 626 (54.0) | 4568 (27.2) | 5187 (46.0) | 8350 (50.1) |
| 1 | 5757 (29.3) | 6528 (38.8) | 3913 (34.7) | 5621 (33.7) |
| 2 | 2028 (10.3) | 3663 (21.8) | 1513 (13.4) | 1933 (11.6) |
| ≥3 | 1264 (6.4) | 2065 (12.3) | 652 (5.8) | 769 (4.6) |
| Missing | 31 | 16 | 17 | 37 |
| Gestation (completed weeks): | ||||
| Mean (SD) | 39.8 (1.1) | 39.8 (1.0) | 39.8 (1.0) | 39.7 (1.0) |
| 37 | 717 (3.6) | 378 (2.3) | 315 (2.8) | 474 (2.8) |
| 38 | 1969 (10.0) | 1568 (9.3) | 978 (8.7) | 1565 (9.4) |
| 39 | 4557 (23.2) | 4089 (24.3) | 2669 (23.7) | 4132 (24.8) |
| 40 | 6976 (35.5) | 6596 (39.3) | 4364 (38.8) | 6492 (39.0) |
| 41 | 4908 (25.0) | 3866 (23.0) | 2821 (25.1) | 3797 (22.8) |
| ≥42 | 523 (2.7) | 302 (1.8) | 108 (1.0) | 195 (1.2) |
| Missing† | 56 | 41 | 27 | 55 |
| Complicating conditions identified at start of care in labour: | ||||
| Prolonged rupture of membranes (>18 hours) | 1462 (7.4) | 395 (2.4) | 231 (2.1) | 383 (2.3) |
| Meconium stained liquor | 1254 (6.4) | 242 (1.5) | 140 (1.2) | 233 (1.4) |
| Proteinuria (≥1+) | 347 (1.8) | 80 (0.5) | 110 (1.0) | 370 (2.2) |
| Hypertension | 502 (2.6) | 92 (0.6) | 78 (0.7) | 113 (0.7) |
| Abnormal vaginal bleeding | 274 (1.4) | 41 (0.2) | 22 (0.2) | 37 (0.2) |
| Non-cephalic presentation | 108 (0.6) | 37 (0.2) | 25 (0.2) | 29 (0.2) |
| Abnormal fetal heart rate | 393 (2.0) | 68 (0.4) | 52 (0.5) | 65 (0.4) |
| Other complications | 54 (0.3) | 14 (0.1) | 17 (0.2) | 17 (0.1) |
| Complications per woman: | ||||
| 0 | 15 794 (80.5) | 15 757 (94.6) | 10 643 (94.5) | 15 512 (93.1) |
| 1 | 3345 (17.0) | 847 (5.1) | 572 (5.1) | 1078 (6.5) |
| ≥2 | 490 (2.5) | 51 (0.3) | 50 (0.4) | 78 (0.5) |
| Missing | 77 | 185 | 17 | 42 |
*Measured with index of multiple deprivation.
†If the recorded “estimated date of delivery” gave a gestational age of ≤31+6 weeks, the birth weight was compared with growth reference centiles,17 and if the birth weight was >95th centile for the recorded gestational age and >5th centile for a gestation of 37+0 weeks, the birth was assumed to be term but the gestation was recoded as missing. A gestation of >44+0 weeks was considered implausible and also recorded as missing.