Table 1. Population demographics.
| Category | Vascular Cases (n = 213) | Normal Controls (n = 161) | Non Vascular Controls (n = 143) | p | Total (%) n = 517 |
| Maternal age in years, mean (median) | 27.95 (28) | 29.8 (30) | 30.98 (30) | <0.00001 | 29.36 (29) |
| Maternal age range (years) | 18–46 | 18–42 | 18–50 | - | 18–50 |
| Ethnicity (no, %) Caucasian | 151 (70.6) | 125 (77.6) | 103 (72.5) | 0.131 (X2 12.5, 8df) | 379 (73.3) |
| Asian | 29 (13.6) | 23 (14.3) | 17 (12.0) | 69 (13.3) | |
| Black | 12 (5.6) | 8 (5.0) | 12 (9.2) | 33 (6.4) | |
| Mixed | 4 (1.9) | 3 (1.9) | 4 (2.8) | 11 (2.1) | |
| Missing data | 18 (8.4) | 2 (1.2) | 5 (3.5) | 25 (4.8) | |
| Primiparous (no, %) | 119 (55.9) | 89 (55.3) | 76 (53.1) | 0.875 (X2 0.27, 2df) | 284 (54·9) |
| Married or cohabiting (no, %) | 168 (78.9) | 135 (83.9) | 112 (78.3) | 0.385 (X2 1.91, 2df) | 415 (80.3) |
| Currently employed (no, %) | 136 (63.8) | 119 (73.9) | 102 (71.3) | 0.09 (X2 4.83, 2df) | 357 (69.1) |
| IMD score, mean (median) | 26.61 (23.74) | 26.89 (24.5) | 25.10 (21.93) | 0.523 | 26.27 (15.02) |
| IMD score range | 2–83 | 2–59 | 1–68 | - | 1–83 |
| Smoking: Current | 32 (15.3) | 21 (13.1) | 18 (12.7) | 0.74 (X2 0.61, 2df) | 71 (13.9) |
| In the last 6 months | 28 (13.4) | 15 (9.4) | 11 (7.7) | 0.16 (X2 3.63, 2df) | 54 (10.6) |
| Missing data | 4 (1.9) | 1 (0.6) | 1 (0.6) | - | 6 (1.2) |
| Alcohol Use: Current | 34 (15.9) | 32 (19.9) | 12 (8.4) | 0.018 (X2 8.03, 2df) | 78 (15.1) |
| In the last 6 months | 81 (37.9) | 77 (47.8) | 46 (32.2) | 0.019 (X2 7.96, 2df) | 204 (39.5) |
| Missing data | 4 (1.9) | 1 (0.6) | 1 (0.6) | - | 6 (1.2) |
| Over the counter: Folic acid | 144 (67.3) | 124 (77) | 104 (72.7) | 0.182 (X2 3.40, 2df) | 372 (72.0) |
| Paracetamol (acetaminophen) | 36 (16.9) | 38 (23.6) | 26 (18.2) | 0.258 (X2 2.71, 2df) | 100 (19.3) |
| NSAID use | 11 (5.1) | 11 (6.8) | 7 (4.9) | 0.721 (X2 0.65, 2df) | 29 (5.6) |
| Codeine/dihydrocodeine* | 9 (4.2) | 2 (1.2) | 5 (3.5) | 0.239 (X2 2.86, 2df) | 16 (3.1) |
| Missing data | 2 (1.2) | 1 (0.6) | 1 (0.6) | - | 4 (0.8) |
| Prescription medication: Antibiotics | 29 (13.6) | 22 (13.7) | 26 (18.2) | 0.735 (X2 0.62, 2df) | 73 (14.1) |
| Other prescription drugs | 38 (17.8) | 40 (24.8) | 30 (21.0) | 0.262 (X2 2.89, 2df) | 108 (20.9) |
| Missing data | 1 (0.6) | 1 (0.6) | 1 (0.6) | - | 3 (0.6) |
NSAID: non-steroidal anti-inflammatory drug; df: degrees of freedom.
*Reported codeine/dihydrocodeine use.