Retrospective study of the effect of remifentanil use during labor on fetal heart rate patterns.

Objective: To investigate possible associations between remifentanil and the appearance of sinusoidal heart rate patterns in fetuses, and neonatal outcomes.

Methods: The present retrospective cohort study included data from patients at over 37 weeks of singleton or multiple pregnancies attending Zuyderland Medical Center, Sittard, the Netherlands, in labor between June 1, and August 31, 2015. Patient data were stratified by whether remifentanil was administered during delivery (remifentanil group) or not (control group), and fetal heart rate tracings were reviewed to identify sinusoidal heart rate patterns.