Can Fetal Heart Rate Responses to Maternal Exercise Be Used for Antepartum Surveillance?

Abstract

The contraction stress test (CST) is currently the only modality used to test for placental insufficiency. It is rarely used due to possible complications. We propose a new test to assess placental reserves by measuring fetal heart rate (FHR) fetal responses to maternal exercise (FRME). A cohort of 640 term patients underwent FRME for accepted clinical indications. There was a total of 1680 tests, performed using a motorized treadmill in a moderate exercise regimen. Monitoring was provided by using standard Philips equipment (Avalon CTS and FM40). FRME was interpreted as negative (absence of decelerations, possible presence of accelerations), positive (presence of late decelerations or sustained bradycardia), or inconclusive. The results demonstrated 1506 tests were negative, 58 were positive, and 312 were inconclusive. If the test was negative, only 2% of the fetuses experienced adverse outcomes, versus 14%, when the test was positive. Positive tests were associated with 29% of category III FHR tracing, 11.6% of 5-minute Apgar score of less than 7, 9.8% admissions to the intensive care nursery, 2.2% of growth restrictions, and 1.2% of fetal or early neonatal demises. FRME if positive is associated with adverse perinatal outcome and could be included into the armamentarium of fetal testing.