Table 3.
Analysis results on influencing factors of fetal loss by univariate conditional logistic regression model
| Influencing factor | Case group (n = 239) | Control group (n = 478) | OR value | 95% CI |
|---|---|---|---|---|
| Education status | ||||
| Postgraduate or above | 11 (4.60) | 69 (14.44) | 1.00 | – |
| Junior high school and below | 63 (26.36) | 35 (7.32) | 11.29 | 5.29–24.11 |
| Senior high school | 39 (16.32) | 34 (7.11) | 7.20 | 3.28–15.78 |
| Undergraduate | 126 (52.72) | 340 (71.13) | 2.33 | 1.19–4.54 |
| Residence in a rural area | 108 (45.19) | 81 (16.95) | 4.03 | 2.84–5.72 |
| Unemployment | 110 (46.03) | 100 (20.92) | 3.22 | 2.30–4.51 |
| Pre-pregnancy BMIa | ||||
| 18.5–23.9 | 167 (69.87) | 381 (79.71) | 1.00 | – |
| < 18.5 | 13 (5.44) | 30 (6.28) | 5.60 | 1.88–16.75 |
| 24.0–27.9 | 42 (17.57) | 60 (12.55) | 3.47 | 1.32–9.10 |
| ≥ 28.0 | 17 (7.11) | 7 (1.46) | 5.54 | 2.26–13.61 |
| Gravidity | ||||
| ≥ 3 | 152 (63.60) | 297 (62.13) | 1.00 | – |
| 1 | 15 (6.28) | 35 (7.32) | 0.84 | 0.44–1.58 |
| 2 | 72 (30.13) | 146 (30.54) | 0.96 | 0.68–1.36 |
| Previous parity | ||||
| ≥ 2 | 37 (15.48) | 40 (8.37) | 1.00 | – |
| 0 | 39 (16.32) | 60 (12.55) | 0.70 | 0.39–1.28 |
| 1 | 163 (68.20) | 378 (79.08) | 0.47 | 0.29–0.76 |
| Preterm birth history | 13 (5.44) | 3 (0.63) | 9.15 | 2.58–32.43 |
| Spontaneous abortion history | 75 (31.38) | 101 (21.13) | 1.71 | 1.20–2.42 |
| Stillbirth history | 2 (0.84) | 2 (0.42) | 0.50 | 0.07–3.54 |
| Congenital malformations history | 10 (4.18) | 9 (1.88) | 0.44 | 0.18–1.09 |
| Hypertensive disorders of pregnancy | 22 (9.21) | 4 (0.84) | 12.01 | 4.09–35.29 |
| Preterm premature rupture of membranes | 14 (5.86) | 8 (1.67) | 3.66 | 1.51–8.84 |
| Velamentous cord insertion | 7 (2.93) | 3 (0.63) | 4.78 | 1.22–18.64 |
| In vitro fertilization and embryo transfer | 22 (9.21) | 24 (5.02) | 1.92 | 1.05–3.50 |
| Pregestational diabetes mellitus | 5 (2.09) | 4 (0.84) | 2.53 | 0.67–9.52 |
| Gestational diabetes mellitus | 23 (9.62) | 37 (7.74) | 1.27 | 0.74–2.19 |
| Fetal growth restriction | 1 (0.42) | 1 (0.21) | 2.00 | 0.13–32.18 |
| Placenta previa | 4 (1.67) | 7 (1.46) | 1.15 | 0.33–3.95 |
| Torsion of cord | 18 (7.53) | 21 (4.39) | 1.77 | 0.93–3.39 |
aThe body-mass index (BMI) is the weight in kilograms divided by the square of the height in meters