Table 2.
Factors associated with stillbirths
| Stillbirths n (%) | Crude RR (95% CI) | Adjusted RR f (95% CI) | |
|---|---|---|---|
| Maternal age group (years)a | P = 0.05; P trend = 0.02 | P = 0.41; P trend = 0.19 | |
| 12-19 | 41 (4.9) | 0.84 (0.61, 1.16) | 0.79 (0.55, 1.12) |
| 20-35 | 400 (5.8) | 1 | 1 |
| 36-50 | 75 (7.5) | 1.29 (1.01, 1.65) | 1.03 (0.76, 1.39) |
| Occupationb | P = 0.02 | P = 0.07 | |
| Skilled | 29 (3.5) | 1 | 1 |
| Semi-skilled | 374 (6.1) | 1.71 (1.17, 2.49) | 1.56 (1.06, 2.30) |
| Unemployed | 89 (5.8) | 1.61 (1.06, 2.45) | 1.59 (1.05, 2.43) |
| Parityc | P = 0.002; P trend = 0.06 | P = 0.04; P trend = 0.23 | |
| 0 | 178 (5.8) | 1.03 (0.86, 1.25) | 1.02 (0.83, 1.26) |
| 1-4 | 277 (5.6) | 1 | 1 |
| 5+ | 52 (9.7) | 1.71 (1.27, 2.30) | 1.56 (1.11, 2.18) |
| Type of delivery | P < 0.001 | P < 0.001 | |
| Spontaneous vaginal delivery | 433 (5.2) | 1 | 1 |
| Breech delivery | 72 (24.3) | 4.69 (3.65, 6.02) | 2.70 (2.04, 3.57) |
| Vacuum extraction | 12 (11.3) | 2.18 (1.23, 3.87) | 2.67 (1.50, 4.76) |
| Number of singleton/multiple births | P = 0.56 | ||
| Singleton | 502 (5.9) | 1 | - |
| Multiple | 15 (5.1) | 0.86 (0.51, 1.44) | - |
| Hypertensive disorder in pregnancy | P < 0.001 | P < 0.001 | |
| No | 453 (5.5) | 1 | 1 |
| Yes | 64 (14.1) | 2.58 (1.98, 3.35) | 1.77 (1.32, 2.36) |
| Sex of babyd | P = 0.14 | - | |
| Female | 232 (5.5) | 1 | - |
| Male | 283 (6.3) | 1.14 (0.96, 1.36) | - |
| Gestation at deliverye | P < 0.001 | P < 0.001 | |
| Term | 359 (4.4) | 1 | 1 |
| Preterm | 157 (26.9) | 6.13 (5.08, 7.39) | 5.15 (4.18, 6.35) |
a1 (0.2%) missing value for age; b25 (4.8%) missing values for occupation; c10 (1.9%) missing values for parity; d2 (0.4%) missing values for sex of baby; e1 (0.2%) missing values for gestation at delivery; fAdjusted for all other variables in the table except number of singleton/multiple births and sex of baby; P-values are based on the Wald test; RR-Relative risk; CI-Confidence interval.