Fetus

Structured Intermittent Auscultation

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Structured Intermittent Auscultation, SIA

  • See Also
  1. Fetal Heart Tracing
  2. Continuous Electronic Fetal Monitoring (CEFM)
  • Contraindications
  1. Does not detect overall Fetal Heart Rate variability
  2. High risk maternal or fetal risk factors
    1. See Continuous Electronic Fetal Monitoring (CEFM) for its specific high risk indications
    2. See Peripartum Risk to the Fetus
  • Requirements
  1. Requires one-to-one nursing (every 15 minute monitoring)
  2. Nurses must be skilled in FHR auscultation
  3. Nurses must be able to palpate contractions
  4. Non-reassuring findings require clinical evaluation
  • Technique
  1. Monitoring frequency
    1. Stage 1:
      1. Low Risk: Every 15-30 minutes
      2. High risk: Every 15 minutes
        1. Continuous Electronic Fetal Monitoring is recommended in high risk cases
    2. Stage 2:
      1. Low Risk: Every 5-15 minutes
      2. High Risk: Every 5 min or after each contraction
        1. Continuous Electronic Fetal Monitoring is recommended in high risk cases
    3. Other indications as needed
      1. Before and after procedure (e.g. AROM, IUPC)
      2. Before and after ambulation
      3. Before and after medication including Anesthesia
      4. Abnormal uterine contraction pattern
      5. After vaginal examination
  2. Procedure
    1. Baseline Fetal Heart Rate (FHR)
      1. Auscultate and count FHR for 60 seconds
      2. Perform between contractions
    2. Fetal response to labor
      1. Auscultate and count FHR for 60 seconds
      2. Perform immediately after contraction
    3. Variability assessment
      1. See FHR Variability
  3. Indications to transition to Continuous Electronic Fetal Monitoring (CEFM)
    1. Irregular Fetal Heart Rate
    2. Fetal Tachycardia (>160 bpm for >10 minutes)
    3. Fetal Bradycardia (<110 bpm for >10 minutes)
    4. Recurrent fetal decelerations after contractions (>50% of contractions)
    5. Prolonged deceleration (2-10 minutes)
  • Efficacy
  1. Decreased rate of cesarean and operative Vaginal Delivery
  2. No increase in unfavorable outcomes compared with Continuous Electronic Fetal Monitoring (CEFM) in low risk patients
  • References
  1. Arnold (2020) Am Fam Physician 102(3): 158-67 [PubMed]
  2. Lewis (2015) Int J Gynaecol Obstet 131(1):9-12 [PubMed]
  3. (2015) J Midwifery Womens Health 60(5): 626-32 [PubMed]