Abstract
Objective
This study aimed to assess clinical efficiency and maternal and neonatal outcomes
for patients who underwent outpatient cervical ripening using mechanical methods (osmotic
dilators and Foley balloon) compared with patients who underwent inpatient ripening.
Study Design
A retrospective cohort study from March 2020 to March 2022 compared patients with
low-risk, term, singleton pregnancies who underwent outpatient cervical ripening to
clinically similar patients who had inpatient ripening. Inverse probability of treatment
weighting for analysis of outcomes to account for differences in groups and comparisons
of outcomes are reported as mean differences with 95% confidence intervals (CIs).
Results
The cohort included 391 patients (116 outpatient, 275 inpatient). Among the outpatient
group, half used only mechanical devices, and all others received additional pharmacological
methods after admission for labor induction. Among the inpatient group, the most common
cervical ripening method was pharmacological only (66.2%), followed by both pharmacological
and mechanical (25.8%), and 8% used only mechanical. After outpatient cervical ripening,
patients had significantly higher cervical dilation (mean difference 1.9 cm, 95% CI:
1.6, 2.3) and simplified bishop scores (mean difference 1.6, 95% CI: 1.2, 2.1) on
admission compared with the inpatient group. The average time from admission to delivery
was 5.8 hours shorter (95% CI: −8.6, −2.9) for the outpatient group compared with
the inpatient group, and the average total length of stay was 7.1 hours shorter (95%
CI: −12.1, −2.1) for the outpatients among patients with vaginal deliveries. Both
groups had similar hours of oxytocin use, and mode of delivery, and did not differ
for maternal complications or neonatal outcomes.
Conclusion
Outpatient cervical ripening using multiple mechanical methods was associated with
significantly higher cervical dilation, shorter average time from patient admission
to delivery, and shorter total length of stay for vaginal deliveries. Outpatient cervical
ripening may be an important option for easing resource utilization for induced labor.
Key Points
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Outpatient cervical ripening resulted in superior cervical dilation and Bishop scores.
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Hospital length of stay was shorter for those receiving outpatient cervical ripening.
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Maternal complications and neonatal outcomes did not differ by setting.
Keywords
cervical ripening - induction - Foley balloon - osmotic dilator - outpatient - Dilapan-S
