Induction of labour using prostaglandin (PGE2) vaginal gel

Abstract

In Australia each year, more than one in four pregnant women will undergo an induction of labour (IOL). PGE2 vaginal gel is the most commonly used IOL method in Australia and is an effective cervical priming agent, although there are no evidence-based recommendations regarding the optimal dosage and frequency of PGE2 vaginal gel that will deliver the safest, most effective, least costly and more positive healthcare experiences for women.The aim of this thesis was to compare two policies of PGE2 vaginal gel for induction of labour at term: a policy of amniotomy once technically possible (regardless of modified Bishop's score (MBS)), versus a policy of giving more PGE2 vaginal gel (repeat administration and amniotomy only when MBS ≥ 7). Four key objectives were addressed across the domains of clinical outcomes, healthcare experience and healthcare costs. A randomised controlled trial was undertaken to determine which policy of PGE2 vaginal gel IOL results in the shorter IOL-to-birth time and is associated with lower rates of obstetric intervention and morbidity. The data from this trial were then used to develop predictive models to help identify those women who might specifically benefit from one policy versus the other. A healthcare experience tool was developed de novo, validated, and the experiences of women who were induced according to a policy of early amniotomy and repeat PGE2, were compared. And finally, the healthcare costs of women in the two arms of the trial were analysed. A decision-analytic model, specifically a Markov chain, was developed to further investigate costs, and a Monte Carlo simulation was performed to confirm the robustness of these findings.This thesis finds that in women being induced with PGE2 vaginal gel, performing an amniotomy (even if the cervix is deemed unfavourable) is likely to result in similar clinical outcomes, but a shorter labour, a more positive healthcare experience, and lower healthcare costs, when compared to giving more PGE2.