Is continuous monitoring the answer to incidentally observed fetal heart rate decelerations?

We examined the interventions and outcomes of pre-term patients with an incidentally identified fetal heart rate (FHR) deceleration and otherwise reassuring FHR pattern admitted for continuous FHR monitoring (FM).

A case series was compiled of patients with at least 36 h of continuous FM secondary to a FHR deceleration. Data on demographics, delivery and perinatal outcomes, medical and obstetric history were extracted from medical records. FHR tracings were reviewed for quantity and type of decelerations.

Ninety-seven patients met inclusion criteria. The median length of time monitored was 4 days with a median of four decelerations a day. Fifty-eight percent of patients were delivered during the same admission primarily for a non-reassuring FHR tracing with a mean delivery gestational age of 33.7 weeks. Patients with resolution of their decelerations delivered at a mean gestational age of 35.8 weeks. No patients with a resolution of decelerations presented later with an intrauterine fetal demise.

Although it is possible that FHR decelerations were markers for adverse outcomes, none of the infants delivered for decelerations had an abnormal cord gas. Because it may lead to pre-term delivery based on false positive testing, clinicians should use caution when prescribing prolonged FM.