Expectant management of preterm premature rupture of membranes at 34 weeks: a cost effectiveness analysis

To examine the outcomes and cost effectiveness of expectant management versus immediate delivery of women who experience preterm premature rupture of membranes (PPROM) at 34 weeks.

A cost-effectiveness model was built using TreeAge software to compare outcomes in a theoretical cohort of 37,455 women with PPROM at 34 weeks undergoing expectant management until 37 weeks versus immediate delivery. Outcomes included fetal death, neonatal sepsis, neonatal death, neonatal neurodevelopmental delay, healthy neonate, maternal sepsis, maternal death, cost, and quality-adjusted life years. Probabilities were derived from the literature, and a cost-effectiveness threshold was set at $100,000 per quality-adjusted life year.

In our theoretical cohort of 37,455 women, expectant management yielded 58 fewer neonatal deaths and 164 fewer cases of neonatal neurodevelopmental delay. However, it resulted in 407 more cases of neonatal sepsis and 2.7 more cases of maternal sepsis. Expectant management resulted in 3,531 more quality-adjusted life years and a cost savings of $71.9 million per year, making it a dominant strategy. Univariate sensitivity analysis demonstrated expectant management was cost effective until the weekly cost of antepartum admission exceeded $17,536 (baseline estimate: $12,520) or the risk of maternal sepsis following intraamniotic infection exceeded 20%.

Our model demonstrated that expectant management of PPROM at 34 weeks yielded better outcomes on balance at a lower cost than immediate delivery. This analysis is important and timely in light of recent studies suggesting improved neonatal outcomes with expectant management. However, individual risks and preferences must be considered in making this clinical decision as expectant management may increase the risk of adverse perinatal outcomes when the risk of puerperal infection increases.