Table 2 Incidence of fore-lying or prolapse of the umbilical cord associated with the use of balloons for cervical ripening during labor among the singleton vertex cases
| Â | Incidence | Odds ratio (95% confidence interval) |
|---|---|---|
Controls (without balloon) | 0.005% (88/1891189) | Reference |
When all cases regardless of the timing of the use of a balloon are calculated | ||
Total Cases | 0.064% (93/146271) | 13.67 (10.21, 18.30) |
  Intra-cervix balloon | 0.018% (10/56065) | 3.83 (1.99, 7.37) |
  Disk shape balloon | 0.060% (23/38348) | 12.90 (8.15, 20.41) |
  Ball type balloon | 0.120% (56/46640) | 25.83 (18.48, 36.12) |
  Others | 0.077% (4/5218) | 16.49 (6.05, 44.92) |
When only cases directly associated with the use of a balloon are calculated (during use and at the time of removal) | ||
Total cases | 0.030% (44/146271) | 6.47 (4.50, 9.29) |
  Intra-cervix balloon | 0.004% (2/56065) | 0.77 (0.19, 3.11) |
  Disk shape balloon | 0.060% (14/38348) | 7.85 (4.46, 13.80) |
  Ball type balloon | 0.037% (28/46640) | 12.91 (8.44, 19.75) |
  Others | 0% (0/5218) | n/a |