(193) Implementation of a standardized protocol for labor induction: a type I hybrid effectiveness-implementation trial

Retrospective data have shown standardization of induction of labor (IOL) may reduce cesarean delivery (CD). Here, we evaluated the impact of prospectively implementing a standardized IOL protocol on obstetric outcomes.

Study Design:

This type I hybrid effectiveness-implementation trial compared 2 years before (PRE) and 2 years after (POST) implementation of a standardized IOL protocol at 2 sites (2018-2022). The protocol had 8 components and recommended active management of labor, frequent cervical exams, and amniotomy by first exam >=4cm. All singletons ≥37 weeks with intact membranes requiring cervical ripening were eligible; prior CD was excluded. The primary effectiveness outcome was CD. Secondary effectiveness outcomes included labor length, chorioamnionitis, and maternal/neonatal morbidity. Poisson regression with robust error variance was used to calculate adjusted relative risks (aRR), with planned stratified analyses by site and parity. Implementation outcomes included fidelity to each protocol component. Feedback on protocol fidelity was distributed to site clinicians POST-implementation every 3 months.

Results:

8509 patients were included (PRE: n=4214, POST: n=4295).  Patients in the POST group had higher BMI and age, more hypertension, less favorable cervices, and differed in IOL indication. There was no difference in CD (PRE: 21.6% v. POST: 21.8%, p=0.85), even when controlling for confounders (aRR 0.99 95%CI[0.90-1.09]; Table). There were no differences in labor length, chorioamnionitis, or neonatal morbidity. Maternal morbidity decreased PRE to POST (21.1% v. 18.0%, p< 0.001; aRR 0.83 95%CI[0.76-0.92]). Stratified results were similar. POST-implementation, fidelity to 4 of 8 protocol components increased significantly, evidenced by more frequent cervical exams, earlier dilation at amniotomy, higher oxytocin doses, and increased IUPC use.  

Conclusion:

Despite increasing standardization of active IOL management, no significant difference in CD was found. The observed decrease in maternal morbidity was unlikely to be a result of the IOL protocol without a change in CD or labor length.