Disputation

6 december 2024, klockan 09:00

Mahdi Amini
Avd. för Obstetrik & Gynekologi, IKVL

Labor induction strategies with Misoprostol: Evaluating oral, outpatient and sequential protocols for improved outcomes

 

 

Handledare: Docent Andreas Herbst, Lunds universitet
Bihandledare: Docent Dag Wide-Swensson, Lunds universitet
Ordförande: Professor Stefan Hansson, Lunds universitet

Opponent
Professor Lone Krebs, Köpenhamn

Lokal: KK Aulan, Jan Waldenströms gata 47, plan 3 Malmö

 

Zoom: https://lu-se.zoom.us/j/62978327108?pwd=8zo4Bm9JzrnUteb5xUy5a7sPmzf3Aw.1
Mötes-ID: 629 7832 7108 Lösenkod: 522225

 

VÄLKOMNA!

 

 

Abstract
Induction of labor (IOL) is one of the most common interventions in obstetric practice today, initiated when awaiting spontaneous labor may pose risks to the mother or fetus. The increasing incidence of IOL globally has been influenced by advancements in fetal monitoring, evolving clinical guidelines, and the development of pharmacological agents such as misoprostol. However, since there are variations in outcomes based on administration routes, protocols, and patient characteristics, there is a need for further investigation to optimize approaches.

The overall aim of this thesis was to evaluate the bioavailability and pharmacokinetic parameters, safety, and clinical efficacy of different misoprostol formulations and induction protocols, focusing on optimizing IOL strategies for better maternal and neonatal outcomes.

Study I: This was a randomized pharmacokinetic study conducted on 72 women admitted for labor induction. The study compared the relative bioavailability of oral and sublingual misoprostol across two different formulations. Results demonstrated that the sublingual route resulted in 20–30% higher bioavailability and faster absorption compared to oral administration. However, bioequivalence between the two compared formulations could not be confirmed, suggesting the need for careful consideration of dosing, formulation and administration routes in clinical practice.

Study II: A retrospective cohort study involving 2,404 women compared the clinical outcomes of oral and sublingual misoprostol for labor induction at Skåne University Hospital in Lund during a 5-year period. The study found that sublingual misoprostol was associated with a higher rate of cesarean section among primiparous women (28.6% vs. 20.5%, p<0.001) compared to oral misoprostol solution. Sublingual was however associated with a higher rate of vaginal delivery within 24 hours for both primiparous and multiparous women. This highlights the need for tailored induction protocols based on parity and other risk factors.

Study III: This was a retrospective study evaluating outpatient versus inpatient labor induction with oral misoprostol in 564 women. The results indicated that outpatient induction significantly reduced the time from admission to delivery compared to inpatient induction (12.8 hours vs. 20.6 hours, p<0.001) without compromising delivery outcomes, suggesting that outpatient induction may be a viable option for certain low-risk pregnancies. The study was not large enough to detect differences in rare outcomes or safety.

Study IV: A retrospective cohort study including 664 nulliparous women with post-term pregnancies examined the effectiveness of sequential labor induction using misoprostol and intracervical balloon catheters. The study found that the sequential method significantly reduced the induction-to-delivery interval (21.8 hours vs. 23.0 hours, p=0.003) without increasing maternal or neonatal complications, indicating a potentially safe and effective option in cases where a faster induction process is wanted.

Conclusions: The findings from these studies underscore the importance of individualized IOL strategies based on patient profiles, including the selection of appropriate misoprostol formulations and induction protocols. While misoprostol is effective for labor induction, careful consideration must be given to the administration route and combination with mechanical methods to optimize outcomes. This thesis supports the development of more standardized and tailored IOL protocols to improve safety and efficacy in diverse clinical scenarios.