- Risk factors associated with each iatrogenic preterm subgroup compared to the term group in multinomial multivariate logistic regression analysis.
| #x00A0; | <32 weeks | #x00A0; | 32–33 weeks | #x00A0; | 34–36 weeks | #x00A0; |
|---|---|---|---|---|---|---|
| Factors | aOR (95% CI)* | P-value | aOR (95% CI)* | P-value | aOR (95% CI)* | P-value |
| Maternal age (years) | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| <20 | 2.103 (1.663–2.660) | <0.001 | 2.221 (1.826–2.701) | <0.001 | 1.449 (1.299–1.615) | <0.001 |
| 20–34 | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| ≥35 | 1.390 (1.207–1.600) | <0.001 | 1.161 (1.018–1.324) | 0.027 | 1.198 (1.126–1.274) | 0.001 |
| Parity | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| 1 | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| ≥2 | 1.331 (1.238–1.514) | <0.001 | 1.287 (1.177–1.406) | <0.001 | 1.181(1.133–1.231) | <0.001 |
| HDP | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| Yes | 3.405 (2.799–4.143) | <0.001 | 4.176 (3.566–4.892) | <0.001 | 2.900 (2.655–3.168) | <0.001 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| GDM | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| Yes | 1.119 (0.889–1.408) | 0.339 | 1.098 (0.896–1.347) | 0.368 | 1.162 (1.059–1.274) | 0.001 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| ICP | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| Yes | 1.280 (0.709–2.312) | 0.413 | 2.775 (1.949–3.950) | <0.001 | 5.299 (4.646–6.044) | <0.001 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| Anemia | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| Yes | 1.235 (0.891–1.711) | 0.204 | 1.575 (1.199–2.070) | 0.001 | 1.092 (0.935–1.275) | 0.269 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| Chorioamnionitis | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| Yes | 11.89 (9.391–15.07) | <0.001 | 3.317 (2.319–4.743) | <0.001 | 2.025 (1.630–2.516) | <0.001 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| Placenta previa | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| Yes | 3.786 (1.682–8.523) | 0.001 | 1.228 (0.305–4.940) | 0.773 | 2.276 (1.398–3.706) | 0.001 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.00 | #x00A0; |
| Placental abruption | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| Yes | 23.68 (10.21–654.9) | <0.001 | 11.236 (23.52–35.87) | <0.001 | 2.404(0.755–7.654) | 0.138 |
| No | 1.000 | #x00A0; | 1.00 | #x00A0; | 1.00 | #x00A0; |
| Fetal distress | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| Yes | 1.487 (1.230–1.799) | <0.001 | 1.479 (1.263–1.779) | <0.001 | 1.071 (0.978–1.173) | 0.141 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
↵* aOR (adjusted odds ration) value and 95% CI (confidence interval) after adjusting for other confounders in Model B (including maternal age, parity, HDP, GDM, ICP, anemia, chorioamnionitis, placenta previa, placental abruption, and fetal distress); the reference group was the term group. P<0.05 was considered significant. Bold values are significant. HDP: hypertension disorders in pregnancy, ICP: intrahepatic cholestasis of pregnancy, GDM: gestational diabetes mellitus.