Conclusion
In this large series of neonates with HIE whose intrapartum care was managed in three academic medical centers approximately two thirds of the cases occurred in the initial setting of moderate variability and/or accelerations on FHR tracing without a sentinel event. A significant proportion of cases also had moderate variability, accelerations, or both in the half hour prior to delivery. The study findings support the concept that diverse clinical scenarios and labor characteristics may be associated with the birth of an infant with HIE, and that moderate variability and/or accelerations may not preclude the development of that disorder. These findings support the notion that risk reduction for HIE will likely involve improvement of management across a range of clinical scenarios, and that some of these outcomes may prove to be unpreventable.