Risk factors associated with each 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; | |
| <20 | 2.084 (1.650–2.632) | <0.001 | 2.197 (1.810–2.666) | <0.001 | 1.437 (1.289–1.601) | <0.001 |
| 20–34 | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| ≥35 | 1.396 (1.213–1.606) | <0.001 | 1.167 (1.024–1.330) | 0.020 | 1.204 (1.132–1.280) | <0.001 |
| Parity | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| 1 | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| ≥2 | 1.369 (1.238–1.514) | <0.001 | 1.332 (1.220–1.455) | <0.001 | 1.218 (1.169–1.269) | <0.001 |
| HDP | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| Yes | 3.564 (2.930–4.335) | <0.001 | 4.418 (3.774–5.173) | <0.001 | 3.044 (2.786–3.326) | <0.001 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| GDM | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| Yes | 1.113 (0.886–1.399) | 0.358 | 1.092 (0.893–1.336) | 0.392 | 1.156 (1.054–1.267) | <0.001 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| ICP | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; |
| Yes | 1.384 (0.766–2.499) | 0.282 | 3.056 (2.147–4.348) | <0.001 | 5.763 (5.049–6.577) | <0.001 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| Anemia | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | |
| Yes | 1.240 (0.896–1.715) | 0.195 | 1.582 (1.207–2.074) | 0.001 | 1.096 (0.939–1.279) | 0.246 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| Chorioamnionitis | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | |
| Yes | 11.06 (8.738–14.02) | <0.001 | 3.023 (2.119–4.314) | <0.001 | 2.247 (2.153–2.344) | <0.001 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.000 | #x00A0; |
| Placenta previa | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | |
| Yes | 40.04 (32.00–50.09) | <0.001 | 13.85 (10.28–18.65) | <0.001 | 9.37 (7.77–11.29) | <0.001 |
| No | 1.000 | #x00A0; | 1.000 | #x00A0; | 1.00 | #x00A0; |
| Placental abruption | #x00A0; | #x00A0; | #x00A0; | #x00A0; | #x00A0; | |
| Yes | 41.52 (25.89–66.58) | <0.001 | 32.06 (20.27–50.70) | <0.001 | 11.67 (7.99–17.02) | <0.001 |
| 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 | 1.477 (1.250–1.746) | <0.001 | 1.061 (0.969–1.161) | 0.201 |
| 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. Bold numbers are significant. HDP: hypertension disorders in pregnancy, ICP: intrahepatic cholestasis of pregnancy, GDM: gestational diabetes mellitus