Determinants of the competing outcomes of intrauterine infection, abruption, or spontaneous preterm birth after preterm premature rupture of membranes^*

Abstract

Objective: Patients with PPROM are at risk for a variety of outcomes, including chorioamnionitis (CA), placental abruption (PA), or preterm labor (PTL). Competing risk regression can analyze a cohort’s risk of individual outcomes while accounting for ongoing deliveries secondary to competing events.

Methods: A secondary analysis of the subjects from MFMU BEAM study of neuroprotection after preterm birth (BEAM) with conservative PPROM management. Deliveries were categorized as: PA, CA, PTL, “elective” or “indicated”. The association between outcomes of PA, CA or PTL and clinical predictors of twins, ethnicity, parity, gestational age at rupture, bleeding, contractions, cervical dilation, preterm birth history, weight, and genitourinary infections were evaluated via competing risk regression.

Result: 1970 subjects were included. The significance and directionality of predictors varied according to specific outcomes. Patients with twins had an increased PTL hazard (1.85) though reductions in CA- (0.66) or PA-specific (0.56) hazards. Decreased latency in African-Americans was almost entirely due to an increased CA hazard (1.44) without a significant association with PTL. Increasing gestational age at membrane rupture was associated with a decreasing hazard of CA although increasing hazard of PTL.

Conclusions: For patients with PPROM, the hazards associated with different clinical predictors vary according to exact outcomes.

• Competing risk analysis
• outcome model
• survival analysis

Acknowledgements

The authors would like to acknowledge the assistance of the NICHD, the MFMU Network and the BEAM Protocol Subcommittee in making the database available. The contents of this report represent the views of the author and do not represent the view of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal Fetal Medicine Units or the National Institutes of Health.

Declaration of interest

The authors report that there are no conflicts of interest.

Notes

* Presentation: This study was presented in abstract form at the Society for Maternal Fetal Medicine meeting in New Orleans, LA 2014.