C2. Maternal cardiac deceleration capacity: a novel insight into maternal autonomic function.

OBJECTIVE: To explore maternal cardiac deceleration capacity (DC), a marker of autonomic function derived from heart rate variability analysis, in pregnancies complicated by intrauterine growth restriction (IUGR) and hypertensive disorders of pregnancy (HDP) associated to IUGR (HDP-IUGR) or to appropriate for gestational age fetuses (HDP-AGAf).

METHODS: Single-center case-control study conducted at Buzzi Children's Hospital, Milan. Maternal electrocardiograms were analyzed by Phase-Rectified Signal Averaging (PRSA) to obtain cardiac beat-to-beat DC in women with: HDP-IUGR; HDP-AGAf; severe-IUGR; mild- IUGR; uncomplicated pregnancies. IUGR was defined as abdominal circumference <5th centile; severe-IUGR was associated with umbilical artery Doppler pulsatility index42SD.

RESULTS: Two- hundred and sixty-nine women recruited. Women with HDP-IUGR (n = 35) showed significantly higher cardiac DC compared both to controls (n = 141) (p = 0.003) and women with HDP-AGAf (n = 18) (p = 0.01). Women with severe-IUGR (n = 14) showed significantly higher DC than controls (p = 0.01). Women with mild-IUGR (n = 61) as with HDPAGAf showed no differences in DC compared to controls (both p = 0.3).

CONCLUSION: Elevated cardiac deceleration capacity proves autonomic alterations in mothers with severe placental failure. We present a new bedside approach to explore maternal autonomic cardiovascular regulation that might reflect the severity of placental vascular insufficiency.