Fetal Health Surveillance (FHS) Part 2 – Electronic Fetal Monitoring* Maternal Newborn Orientation Learning Module Reproductive Care Program of Nova Scotia, 2012 *FHS: Part 1 should be viewed prior to review of this module

References www.sogc.org

Objectives Review skilled use of the electronic fetal monitor (EFM) during labour Risks/benefits of electronic fetal monitoring Indications Methods of electronic fetal monitoring Analysis, interpretation and classification of tracings Appropriate interventions in the event of atypical or abnormal tracings Communication and documentation

Risks/benefits Some association with a reduction in neonatal seizures; no difference in cerebral palsy or perinatal mortality  in C-sections and operative vaginal births

SOGC Recommendation (2007) ‘The normal, healthy fetus is well-equipped to withstand the repeated, transient hypoxia associated with labour contractions.’ ‘Intermittent auscultation (IA) is the preferred method of fetal surveillance for healthy women without risk factors for adverse outcomes’. For those at risk for adverse outcomes, electronic fetal monitoring is advised.

Indications for using the EFM Examples of risk factors for ‘adverse outcomes’: Antepartum maternal HDP  Hemorrhage Diabetes  Morbid Obesity Antepartum fetal Prematurity  Oligohydramnios IUGR  Multiple pregnancy

Indications for using the EFM Examples of risk factors for ‘adverse outcomes’: Intrapartum maternal Prolonged ROM  Postterm pregnancy > 42+0 Previous C/S  Augmented/induced labour* Intrapartum fetal Meconium staining Abnormal FHR on auscultation *Augmentation  continuous EFM * Induction  EFM can be interrupted periodically once the infusion is stable, and provided there are no additional risks and the tracing has been normal

Methods of electronic fetal monitoring

Applying the external EFM Leopold’s Maneuver

Internal Fetal Monitoring IUPC Scalp electrode

Equipment - Monitor Paper 20 bpm 10 sec. 1 minute

Quality of the tracing – FHR

Quality of the tracing - contractions Cont’n Cont’n

Features of the tracing Contractions FH Baseline Variability Accelerations Decelerations

Contractions Estimate frequency from the start one contraction to the start of the next Duration estimated in seconds Estimate over 10 min Document range  ‘q 2-3 min x 50-60 sec’ Resting tone ‘soft’ or ‘firm’ by palpation; approx. 20 mmHg measured by IUPC frequency Resting tone

Abnormal contraction patterns Tachysystole – more than 5 contractions in 10 minutes, averaged over 30 minutes Hypertonus – resting tone > 20 to 25 mmHg

Baseline FHR Approximate mean of the FHR (rounded to 5 bpm) assessed over 10 minutes Excludes accelerations and decelerations Normal baseline 110 to 160bpm

Tachycardia Causes: Prematurity Maternal anxiety/medication Prolonged fetal activity Fever/infection Chronic fetal hypoxemia Baseline > 160 bpm x > 10 min

Bradycardia Causes: Postmaturity Fetal heart block Vagal stimulation Fetal hypoxia/acidosis (late sign) Atypical if baseline 100 to 110 bpm; Abnormal if baseline < 100 bpm

Variability Refers to fluctuations in the baseline FHR Occurs because of push and pull between sympathetic nervous system (pushes the FHR up) and parasympathetic nervous system (pulls the FHR down) Requires an intact, well functioning nervous system and oxygenated brain stem

Variability To determine variability: 120 150 180 90 To determine variability: Select a 1-minute section of the tracing Look at the amplitude/range of fluctuations Ensure there is a minimum of 2 fluctuations/cycles within the minute CMNRP Average # of cycles – 2 to 4/min Moderate variability (amplitude) – 6 to 25 bpm

Classification of variability Absent – range undetectable Moderate 6-25 bpm Minimal ≤ 5 bpm Marked > 25 bpm

Minimal or absent variability Causes: Fetal sleep Prematurity Medications Hypoxia/acidemia Atypical – if ≤ 5 bpm x 40 to 80 min Abnormal – if ≤ 5 bpm x > 80 min

Marked Variability Causes: Uncertain etiology Mild hypoxia Catecholamines Abnormal – if ≥ 25 bpm x > 10 minutes *rule out artifact

Accelerations Causes: Normal response of a well-oxygenated, non- acidotic fetus to sympathetic stimulation or fetal activity If not spontaneous, may be elicited by fetal scalp stimulation Abrupt increases in the FHR at least 15 bpm above the baseline, lasting 15 sec to 2 min (> 32 weeks gestation)

Describe this tracing including features reviewed so far

Decelerations - Early ‘Mirror image’ of contractions Nadir of deceleration occurs with peak of contraction; FHR returns to baseline as the contraction ends Mechanism – vagal response from head compression Benign CMNRP

Decelerations - Late Gradual decrease in the FHR with nadir after peak of contraction and gradual return to baseline following the contraction Deceleration may be almost undetectable; nadir usually not more than 10 to 20 bpm below the baseline Mechanism – uteroplacental insufficiency CMNRP Chronic/Acute Conditions

Decelerations - Late

Decelerations - Late

Decelerations - Variable 120 150 180 90 100 25 50 75 Abrupt decrease in the FHR, at least 15 bpm below the baseline, lasting ≥ 15 seconds and < 2 minutes Uncomplicated variables have ‘shoulders’ – accelerations before and following decel Mechanism – cord compression CMNRP Normal if occasional; Atypical if repetitive (≥ 3)

Complicated variable decels  to < 70 bpm x > 60 seconds Loss of variability Slow return to baseline Baseline continues at a lower rate Prolonged secondary acceleration (overshoot) Biphasic Tachycardia or bradycardia CMNRP Overshoot Biphasic

Prolonged decelerations In FHR ≥ 15 bpm below baseline (most often ≥ 30 bpm), lasting ≥ 2 min, < 10 min Possible causes include cord prolapse, hypertonus, uterine rupture, and sudden fetal descent

Rare, distinctive tracings

Classification of EFM Tracings (SOGC, 2007) Parameter Normal Atypical Abnormal Baseline 110 to 160 bpm Bradycardia 100 to 110 bpm Tachycardia > 160 bpm x > 30 min to < 80 min Rising Baseline Bradycardia < 100 bpm Tachycardia >160 bpm x > 80 min Erratic baseline Variability 6 to 25 bpm ≤ 5 bpm x < 40 min ≤5 bpm x 40-80 min. ≤ 5 bpm x > 80 min ≥ 25 bpm x > 10 min Sinusoidal Decelerations None or occasional uncomplicated variables Early decels Repetitive (≥ 3) uncomplicated variables Occasional lates Single prolonged > 2 min, < 3 min Repetitive (≥ 3) complicated variables Lates >50% of contractions Single prolonged >3, < 10 min Accelerations Spontaneous accelerations Accelerations with scalp stimulation No acceleration with fetal scalp stimulation Usually absent

Recommended actions Normal Atypical Abnormal Action May interrupt EFM for periods up to 30 minutes if condition stable and oxytocin rate stable Further assessment required Review overall clinical situation; scalp pH may be obtained; prepare for delivery pH > 7.25 – continue monitoring; repeat scalp gas in 30 minutes if atypical or abnormal tracing persists pH 7.20 to 7.25 - repeat scalp gas in 30 minutes pH <7.20 – delivery is advised

Atypical/Abnormal Tracings Clinical Evaluation is essential: Are there health, pregnancy or labour complications? What is the labour status and progress? Is labour spontaneous or induced? Is the fluid clear or meconium stained? Is this pattern an abrupt change? How was the earlier tracing?

Interventions in response to abnormal features May be specific to the atypical/abnormal features, as appropriate Variable decelerations  cord compression  relieve pressure on the cord change maternal position consider V/E to assess for cord prolapse Tachycardia check maternal temperature promote intrauterine resuscitation

Interventions in response to abnormal features Late decelerations  uteroplacental insufficiency  maximize uteroplacental blood flow left lateral maternal position promote intrauterine resuscitation Minimal/absent variability for > 40 minutes scalp stimulation to elicit accelerations

Promoting intrauterine resuscitation Discontinue oxytocin Position change/left lateral position  IV rate to improve hydration Modify breathing and pushing techniques (2nd stage) Administer oxygen at 8-10 l/min* *Prolonged use of oxygen should be avoided; its effectiveness varies depending on the clinical situation; increases fetal pO2 only slightly.

G1, 40 3/7 wks; SRM x 26 hours, spontaneous labour, 3 cm, ‘0’

G1 induced for HDP at 40 4/7 wks; 4 cm dilated, station ‘0’, strong contractions, meconium stained fluid

Communication Always keep the labouring woman informed of findings of FHS including rationale for interventions Effective, interprofessional communication is essential Suboptimal communication was identified as a ‘root cause’ in 72% of reported adverse outcomes

Communication tools SOGC recommends ‘CHAT’ C – Current Condition H – History A – Assessment T – Treatment SBAR is commonly used in NS S – Situation B – Background A – Assessment R – Recommendation

Documentation-clear, concise, and accurate Contraction pattern and details of the FHR q 15 to 30 minutes during active labour (q15 minutes when oxytocin running), and every 5 minutes during 2nd stage. Tracing interpretation/classification Actions undertaken to improve atypical or abnormal tracings Plan of care

Legal ‘protection’ Consistent terminology and classification Regular interprofessional education and review of tracings Effective communication and complete documentation Consistent ‘times’ on a high quality tracing, in the partogram and throughout the record Each portion of the tracing labeled; do not circle or mark ‘suspicious’ findings but do note adjustment of transducers and/or tocodial

In summary Regular interprofessional education related to fetal health surveillance and electronic fetal monitoring is essential for all health care providers who care for labouring women. This education should promote consistent terminology and a common approach that is based on current SOGC guidelines and standards of care. Regular education related to EFM (and other methods of FHS) that includes recommended terminology, classification of tracingis essential

Thank you! We welcome your feedback. Please take a few moments to complete a short evaluation: http://rcp.nshealth.ca/education/learning-modules/evaluation If you have any questions, please contact the RCP office at rcp@iwk.nshealth.ca or 902-470-6798