Table 2.
Primary and secondary maternal and neonatal clinical effectiveness outcomes compared among the pre- and post-implementation groups of a standardized protocol for labor induction.
| Pre (n = 4214) n (%) | Post (n = 4295) n (%) | p-value | Adjusted Relative Risk (aRR) [95% Confidence Interval]a | |
|---|---|---|---|---|
| Primary outcome: cesarean delivery | 912 (21.6) | 937 (21.8) | 0.85 | 0.99 [0.90–1.09] |
| Secondary maternal outcomes | ||||
| Time to delivery (hours)b,c | 17.4 [11.8–25.1] | 18.0 [12.0–26.4] | 0.012 | 0.97 [0.88–1.06]d |
| Length of latent labor (hours)c,e | 14.6 [9.9–21.4] | 14.9 [10.0–22.2] | 0.051 | 0.99 [0.91–1.09]d |
| Length of active labor (hours)c,f,g | 1.0 [0–3.0] | 1.0 [0–3.2] | 0.37 | 0.95 [0.86–1.04]d |
| Length of second stage (hours)c,h | 0.9 [0.3–1.7] | 1.0 [0.3–1.7] | 0.019 | 0.96 [0.87–1.05]d |
| Chorioamnionitis | 478 (11.3) | 435 (10.1) | 0.070 | 0.90 [0.79–1.02] |
| Postpartum hemorrhage | 590 (14.3) | 532 (12.6) | 0.024 | 0.85 [0.76–0.96] |
| Composite maternal morbidityi | 393 (9.3) | 277 (6.5) | <0.0001 | 0.67 [0.58–0.79] |
| Endometritis | 66 (1.6) | 44 (1.0) | 0.027 | 0.63 [0.43–0.92] |
| Blood product transfusion | 151 (3.6) | 118 (2.7) | 0.028 | 0.75 [0.59–0.96] |
| Wound infection or separation | 87 (2.1) | 75 (1.7) | 0.28 | 0.82 [0.60–1.12] |
| Venous thromboembolismj | 4 (0.1) | 5 (0.1) | 0.42 | – |
| Hysterectomy | 0 (0) | 0 (0) | NA | – |
| Intensive care unit admissionj | 14 (0.3) | 8 (0.2) | 0.21 | – |
| Readmission | 118 (2.8) | 71 (1.7) | <0.0001 | 0.58 [0.43–0.78] |
| Death | 0 (0) | 0 (0) | NA | – |
| Primary indication for cesareank | 0.56 | – | ||
| Non-reassuring fetal status | 382 (41.9) | 358 (38.2) | ||
| Arrest of descent | 137 (15.0) | 135 (14.4) | ||
| Arrest of dilation in the active phase | 126 (13.8) | 132 (14.1) | ||
| Failed induction/latent phase arrest | 181 (20.0) | 230 (24.6) | ||
| Maternal request | 29 (3.2) | 25 (2.7) | ||
| Umbilical cord prolapse | 13 (1.4) | 18 (1.9) | ||
| Otherl | 44 (4.8) | 39 (4.2) | ||
| Cervical dilation at cesarean (cm)c,k | 5 [4–8.5] | 5 [4–8] | 0.92 | – |
| Maternal length of stay postpartum (days)c | 1.6 [1.2–1.9] | 1.5 [1.1–1.9] | <0.0001 | – |
| Secondary neonatal outcomes | ||||
| Composite neonatal morbiditym | 103 (2.4) | 121 (2.8) | 0.28 | 1.18 [0.90–1.54] |
| NICU admission >48 hn,o | 198 (44.1) | 253 (43.9) | 0.96 | 1.02 [0.84–1.23] |
| Neonatal length of stay (days)c | 1.6 [1.2–2.0] | 1.5 [1.1–2.0] | <0.0001 | – |
Adjusted for body mass index, history of pregestational diabetes, hypertensive history, indication for induction, modified Bishop score, starting induction agent, and maternal age.
Defined as time from start of induction to delivery.
Median Interquartile range [IQR].
Adjusted Hazard Ratio (HR) with 95% CI, censored for cesarean where applicable.
Time from start of induction to first exam at ≥6 cm or delivery if active labor was not reached.
First exam at ≥6 cm to delivery.
Among those who reached active labor.
Among those who recached second stage.
≥1 of the following: endometritis, blood transfusion, wound infection or separation (requiring intervention), venous thromboembolism, hysterectomy, intensive care unit admission, readmission, and death within 30 days of delivery.
Adjusted analysis not performed due to small sample size.
Among those who underwent cesarean.
Example of other indications included malpresentation diagnosed during labor, worsening placental abruption, worsening preeclampsia remote from delivery, and failed operative delivery.
Defined as ≥1 of the following: severe respiratory distress, culture-proven sepsis requiring antibiotic therapy, neonatal hypoxic-ischemic encephalopathy, intraventricular hemorrhage, or neonatal death.
Neonatal intensive care unit (NICU).
Among those who went to the NICU.