Table 2.
Unadjusted risks for sPTB according to some maternal medical history and habits.
| Characteristics | sPTB | Controls | RR (95%CI) |
|---|---|---|---|
| Smoking | |||
| No smoking | 73 (93.6%) | 962 (92.5%) | Ref. |
| Ceased during pregnancy or smoker | 5 (6.4%) | 78 (7.5%) | 0.85 [0.23–3.23] |
| Alcohol drinkinga | |||
| No alcohol | 56 (83.6%) | 757 (83.5%) | Ref. |
| Ceased before 1st visit | 8 (11.9%) | 142 (15.7%) | 0.77 [0.34–1.75] |
| Current drinker at 1st visit | 3 (4.5%) | 8 (0.9%) | 3.96 [1.04–15.05] |
| Other Drugsb | |||
| Never | 61 (95.3%) | 839 (94.6%) | Ref. |
| Ceased before 1st visit | 1 (1.6%) | 39 (4.4%) | 0.37 [0.03–5.18] |
| Current user at 1st visit | 2 (3.1%) | 9 (1.0%) | 2.68 [0.86–8.33] |
| Previous maternal conditions | |||
| Yes | 15 (19.2%) | 130 (12.5%) | 1.60 [0.89–2.86] |
| No | 63 (80.8%) | 910 (87.5%) | Ref. |
| Previous abortion | |||
| Yes | 9 (11.5%) | 117 (11.3%) | 1.03 [0.33–3.19] |
| No | 69 (88.5%) | 923 (88.7%) | Ref. |
| Mother’s History of PTBc | |||
| Yes | 8 (11.0%) | 98 (9.9%) | 1.11 [0.24–5.18] |
| No | 65 (89.0%) | 890 (90.1%) | Ref. |
| Mother’s History of LBWd | |||
| Yes5 | 5 (7.2%) | 111 (11.7%) | 0.61 [0.17–2.20] |
| No | 64 (92.8%) | 839 (88.3%) | Ref. |
| Sister’s History of PTBe | |||
| Yes | 4 (12.5%) | 22 (7.3%) | 1.69 [0.52–5.48] |
| No | 28 (87.5%) | 279 (92.7%) | Ref. |
| Sister’s History of LBWe | |||
| Yes | 4 (12.5%) | 32 (10.6%) | 1.18 [0.16–8.91] |
| No | 28 (87.5%) | 269 (89.4%) | Ref. |
| Total | 78 | 1,040 | |
Missing information for: a144; b167; c57; d99; e17.
LBW: low birth weight; PTB: preterm birth. Values in bold mean they are statistically significant.