Multivariate logistic regression analyses with potential significant factors and predictors associated with catheter insertion success rates
| Variables | Catheter insertion success rate N (%) | Adjusted OR | 95% CI for OR | P value |
| Gestational age (week) | 29.56±4.20 vs 29.53±5.12 | 1.23 | 1.03 to 1.44 | 0.015 |
| Number of pricks | ||||
| 1 prick 2 pricks ≥3 pricks | 833 (99.3) 244 (79.5) 121 (63.7) | 1.0 (reference) 0.07 0.02 | 0.01 to 0.57 0.01 to 0.13 | 0.014 0.001 |