TABLE 2.
Frequency of IOL and EM by gestational age. Frequency of CB by each labor management approach and by gestational age, comparison to IOL
| Induction of Labor |
Inclusive expectant management |
Exclusive expectant management |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| n (% GA week) | Cesarean birth |
n (% GA week) | Cesarean birth |
n (% GA week) | Cesarean birth |
||||
| n | % (CI) | n | % (CI) | n | %(CI) | ||||
| 37th week | 68 (1.7) | 13 | 19.1 (11.4–30.2) | 3989 (98.3) | 774 | 19.4 (18.2–20.6) | 3882 (98.3) | 762 | 19.6 (18.3–20.9) |
| 38th week | 115 (2.9) | 29 | 25.2 (18.1–33.9) | 3767 (97.0) | 733 | 19.5 (18.2–20.8) | 3452 (96.8) | 707 | 20.5 (19.1–21.8) |
| 39th week | 186 (5.4) | 43 | 23.1 (17.6–29.7) | 3266 (94.6) | 664 | 20.3 (18.9–21.7) | 2464 (92.9) | 568 | 23.1 (21.4–24.7) |
| 40th week | 214 (8.7) | 47 | 21.9 (16.9–28.0) | 2250 (91.3) | 521 | 23.2 (21.5–24.9) | 1161 (15.6) | 348 | 29.9 (27.3–32.6)* |
| 41st week | 452 (38.9) | 155 | 34.3 (30.1–38.8) | 709 (61.1) | 193 | 27.2(24.1–30.6)** | 199 (30.6) | 78 | 39.2 (32.4–46.0) |
| 42nd week + | 137 (68.8) | 60 | 43.8 (35.7–52.3) | 62 (31.2) | 18 | 29.0(19.1–41.5)* | 62 (31.2) | 18 | 29.0 (17.4–40.7)* |
Note: Definitions: Inclusive EM includes all labors within and beyond the week when IOL was performed. Exclusive EM excludes spontaneous labors during the index week and counts all labors after the week IOL was performed.
Abbreviations: CI, confidence interval; EM, expectant management; IOL, induction of labor; OR, odds ratio.
Post hoc power calculation (IOL vs inclusive EM): 37th week = 2.8%, 38th week = 34.1%, 39th week = 15.9%, 40th week = 6% power, 41st week = 72.8%. (IOL vs exclusive EM): 37th week = 3%, 38th week = 24.6%, 39th week = 2.6%, 40th week = 67.4% power, 41st week = 22.6%, 42nd week = 50.9%.
P-value <0.05 (IOL vs EM).
P-value <0.01 (IOL vs EM).