Table 3.
Distribution of study population according to other suspected risk factors.
| Variables | Cases (no.) | Controls (no.) | OR | 95% CI | P value |
| Parity | |||||
| 0–2 | 112 | 111 | 1.00 | - | - |
| 3 | 23 | 24 | 0.95 | 0.52–1.75 | NS |
| 4 | 22 | 24 | 0.91 | 0.49–1.68 | NS |
| 5+ | 43 | 41 | 1.06 | 0.65–1.72 | NS |
| all categories | 200 | 200 | - | - | - |
| Risk variables of present pregnancy | |||||
| cervical incompetence | 47 | 18 | 3.11 | 1.73–5.58 | <0.001 |
| multiple pregnancy | 19 | 3 | 6.89 | 2.00–23.69 | <0.001 |
| accidental hemorrhage | 9 | 4 | 2.31 | 0.70–7.64 | NS |
| genital tract infection | 48 | 45 | 1.09 | 0.69–1.74 | NS |
| Obstetric history | |||||
| previous PTB | 30 | 1 | 35.12 | 4.74–260.32 | <0.001 |
| abortion | 3 | 1 | 3.03 | 0.31–29.38 | NS |
| PPROM | 14 | 10 | 1.43 | 0.62–3.30 | NS |
| Medical disease | |||||
| typhoid fever | 16 | 7 | 2.40 | 0.97–5.97 | NS |
| diabetes | 2 | 1 | 2.01 | 0.18–22.35 | NS |
| urinary tract infection | 82 | 40 | 2.78 | 1.78–4.35 | <0.001 |
| Emotional disturbances | |||||
| severe fright | 67 | 63 | 1.10 | 0.72–1.67 | NS |
| anxiety | 87 | 60 | 1.80 | 1.19–2.72 | <0. 01 |
| antenatal visits due to pregnancy complications | |||||
| 0 | 25 | 30 | 1.00 | - | - |
| 1–3 | 65 | 95 | 0.53 | 0.35–0.80 | <0.001 |
| ≥4 | 110 | 75 | 2.04 | 1.37–3.04 | <0.001 |
| cigarette smoking | |||||
| smokers | 4 | 5 | 0.80 | 0.21–3.02 | NS |
| long travel and trauma to abdomen | |||||
| history of long travel | 61 | 65 | 0.91 | 0.60–1.39 | NS |
| trauma to abdomen | 45 | 14 | 3.86 | 2.04–7.30 | <0.001 |