NUR 134 M. Johnston, RN-BC, M.Ed.

Types of Monitoring Auscultation- listen to fetal heart rate (FHR) Electronic Fetal Monitoring – use of instruments to record FHR and uterine contractions(U/Cs)

Auscultation Doppler - ultrasound converts sounds waves to signals of fetal heart Fetoscope - Like stethoscope, open end pressed on abdomen, used less frequently

Electronic Fetal Monitoring Measures response of FHR to uterine contractions (U/Cs) Intermittent or Continuous External Ultrasound transducer Tocotransducer Internal Fetal Scalp Electrode Intrauterine Pressure Catheter

Fetal Heart Rate Characteristics Evaluate to determine fetal status NICHD terminology Baseline Rate Baseline Variability Accelerations (present or absent) Decelerations (present or absent) Changes or trends over time

Baseline (BL) Normal range bpm Measure between U/Cs for 10 min. period Tachycardia - >160 bpm for >10 minutes Bradycardia - 10 minutes

Classifications of FHR Variability Fluctuations in FHR, irregular in frequency and amplitude Absent 0-2 bpm Minimal >2 <6 bpm Moderate bpm Marked >25 bpm

Accelerations Abrupt increase in FHR above BL Present or Absent < 32 wks gestation Peak ≥ 10 bpm above BL for at least 10 sec. >32 wks gestation Peak ≥ 15 bpm above BL for at least 15 sec. Accel ≥ 10 min. is defined as BL change

Accelerations Abrupt increase in FHR above BL Peak ≥ 15 bpm above BL for at least 15 sec.

Types of Decelerations Early – Gradual decrease and return to BL, mirrors the U/C Variable – Abrupt (<30 sec) decrease (≥15 sec down, lasting ≥ 15 sec and <2 min from onset to return to BL) Late – Gradual decrease (≥30 sec) and gradual return to BL; delayed timing nadir occurs after peak of U/C Prolonged – Decrease in FHR below BL ≥15 sec, lasting ≥ 2 min. but <10 min.

Early Deceleration Gradual decrease and return to BL Mirrors the U/C

Variable Deceleration Abrupt (<30 sec) decrease (≥ 15 sec down, lasting ≥ 15 sec and < 2 min. from onset to return to BL)

Late Deceleration Gradual decrease (≥ 30 sec) and gradual return to BL Delayed timing, nadir occurs after peak of U/C

Prolonged Deceleration Decrease in FHR below BL ≥ 15 sec, lasting ≥ 2 min. but < 10 min.

FHR Interpretation Information about fetal oxygenation/placental function Somewhat subjective Abnormal patterns may need further testing

Monitoring Uterine Contractions Assess U/C pattern while assessing FHTs External Palpation EFM Toco measures frequency, duration Noninvasive Internal Intrauterine pressure catheter (IUPC) Measures exact intrauterine pressure Invasive

Why Monitor?

Interventions Abnormal FHR pattern: Change maternal position Give oxygen via mask Increase IV fluids Consider medication to relax uterus

Other Fetal Surveillance Non-Stress Test (NST) - EFM Biophysical Profile (BPP) - U/S Doppler Flow Studies - U/S Fetal Movement Count-maternal sensation/palpation