Table 3.
Multivariate logistic regression model of risk factors for preterm delivery
| Parameter | OR | 95% CI | P- value |
|---|---|---|---|
| Age(years) | |||
| < 35 | – | – | – |
| ≥ 35 | 1.64 | 1.01–2.44 | 0.015 |
| Ethnic | |||
| Tork | – | – | – |
| Lor | 4.55 | 2.50–8.29 | 0.001 |
| Fars | 4.07 | 2.72–6.09 | 0.001 |
| Kord | 5.80 | 2.74–12.28 | 0.001 |
| Arab | 1.71 | 0.50–5.80 | 0.484 |
| Balooch | 9.72 | 3.07–30.78 | 0.001 |
| Torkaman | 3.25 | 1.77–5.97 | 0.001 |
| Else | 3.69 | 0.85–16.09 | 0.108 |
| Regular Cycles of period | |||
| Yes | – | – | – |
| No | 1.77 | 1.14–3.01 | 0.001 |
| Gap pregnancy(years) | |||
| Upper than 3 | – | – | – |
| Lower than 1 | 1.85 | 1.14–3.01 | 0.012 |
| 1–3 | 0.81 | 0.60–1.11 | 0.198 |
| Primary pregnancy | 1.43 | 1.08–1.88 | 0.011 |
| Consanguineous marriage | |||
| No | – | – | – |
| Yes | 1.32 | 1.04–1.67 | 0.019 |
| Abortion history | |||
| No | – | – | – |
| Yes | 1.57 | 1.08–2.27 | 0.016 |
| Stillbirth history | |||
| No | – | – | – |
| Yes | 3.92 | 2.76–5.57 | 0.001 |