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ANTENATAL & INTRAPARTUM Electronic Fetal Heart Rate Monitoring :





Resources: Cochrane database RCOG Guidelines. NICE Guidelines (U.K). ACOG Guidelines My personal experience

Electronic Fetal Monitoring- Introduction:

Electronic Fetal Monitoring- Introduction Pioneered in 1958 in USA and Europe Commercially available 1968 Needs to be viewed in conjunction with other assessment e.g. FBS and clinical situation. Should be used for the right reason and with appropriate degree of skill.

PowerPoint Presentation:

Electronic FHR monitoring is a screening test that provides information to alert the clinician that a true test for fetal welfare assessment needs to be performed, e.g : fetal blood sampling . CTG as a screening test

CTG as screening test ::

CTG as screening test :

An ideal screening test ::

An ideal screening test :

CTG as a screening test:

CTG as a screening test

EFM Problems and Realities:

EFM Problems and Realities Difficulties with interpretation over confidence Difference in opinion between practitioners but, also when the same practitioner examines the same CTG twice.

EFM- Facts:

EFM- Facts ??? Reliability of interpretation 50-75% are false positive . Positive predictive value = Is the chance that a screened positive individual will have the disease. For CTG this is never more than 50% i.e. at least 50% of the time it will be unnecessarily alarming

CTG as a Screening Test:

Poor positive predictive value Up to 50% of fetuses with an abnormal CTG will be hypoxic and acidotic but 50% will be OK High negative predictive value >98% of fetuses with a normal CTG will be OK CTG as a Screening Test

A screening test is more likely to be a true positive if:

A screening test is more likely to be a true positive if It is positive in a high risk group So always consider the clinical context


ANTENATAL CTG Pregnancy may be complicated by conditions that need additional ways of assessment of fetal well-being. These conditions include medical problems in the mother, which may impact on the fetus.

PowerPoint Presentation:

The basis for performing and interpreting the antenatal CTG is the belief that the ’normal’ CTG reflects well, uncompromised fetus and that certain abnormalities indicate an increased possibility of fetal compromise.


MATERNAL INDICATION : Essential hypertension Pre- eclampsia Renal disorders Autoimmune disease Maternal diabetes Thyroid disease Prolonged pregnancy Vaginal bleeding Reduced fetal movements Prolonged ruptured membranes


FETAL INDICATIONS : Intrauterine growth restriction fetal infection multiple pregnancies

PowerPoint Presentation:

Antenatal cardiotocography for fetal assessment (Review) 2010, The Cochrane Collaboration.

PowerPoint Presentation:

Antenatal CTG is a commonly used form of fetal assessment in pregnancy and uses the fetal heart rate as an indicator of fetal well-being (Boyle 2004). It may be used in isolation, sometimes referred to as the ‘non-stress test’ or with the stimulation of uterine activity to see how the fetal heart responds, sometimes known as the ‘contraction stress test’ (Owen 2001).

PowerPoint Presentation:

Antenatal CTG is most commonly performed in the third trimester of pregnancy (after 28 weeks). The gestational age at which CTG commences varies in practice, and depends on the minimum age of survival in the local neonatal unit and therefore in some institutions may be used even before 26weeks’ gestation (Smith 1987). -- TIMING

PowerPoint Presentation:

Antenatal CTG should be used in combination with other methods of fetal assessment such as ultrasound, Doppler studies, amniotic fluid volume measurement and as part of a formal biophysical profile( Turan 2008), ANTENATAL CTG

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Frequency of testing varies widely in practice, depending on the indication for the CTG and gestational age, and ranges from weekly to three times a day. -- Frequency

PowerPoint Presentation:

Computerized fetal heart rate analysis systems have been developed to allow the automated evaluation of the CTG through numerical indices with the aim of bringing objectivity and reliability to CTG interpretation (Dawes 1992). It is also thought that the computerised CTG analysis system may be able to extract more diagnostic information from the fetal heart rate signal than visual analysis alone (Valensise 2006). Computerized analysis of CTG traces

How to interpret:

How to interpret The accepted ’normal’ limits for fetal heart rate parameters are the same; • Baseline fetal heart rate of 110 -160 beats per minute. • Baseline variability should be greater than five beats per minute . • Presence of two or more accelerations of the fetal heart rate exceeding 15 beats per minute, sustained for at least 15 seconds in a 20-minute period - this pattern is termed reactive . • Absence of decelerations.

How to react:

How to react When an antenatal CTG is performed and interpreted as abnormal , this may result in a range of further actions . These could include further testing, hospital admission, induction of labour or caesarean section.

How to react:

Is important that the caregiver understands the potential advantages and disadvantages of the application of the test before the test is offered to the woman , including information about further testing that it may lead to . How to react

PowerPoint Presentation:

-- Initial observational studies showed a strong correlation between an abnormal CTG and poor fetal outcome . (Freeman 1982). -- In high-risk pregnancies in particular,’non-reactive’ CTGs were associated with increased morbidity and mortality for the baby (Boehm 1986; Flynn 1977). -- Early studies investigating the observer reliability of antenatal CTGs recognised that correct assessment of CTGs was not always easy (Trimbos 1978a). EVIDENCE-BASED FACTS

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This observation has led to the belief that performance of a CTG would allow early identification of fetal heart rate changes associated with hypoxia and allow subsequent early intervention with improved outcomes EVIDENCE-BASED FACTS

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However, later studies have demonstrated a lack of specificity and high false positive rates when using the CTG to detect fetal compromise . (Sadovsky 1991; Trimbos 1992). EVIDENCE-BASED FACTS

PowerPoint Presentation:

-- False negative results, false reassurance of fetal well- being for the mother and the health practitioner. -- False positive result, unnecessary procedures or Interventions for mother or fetus and increased use of healthcare resources. -- frequent antenatal CTGs in high-risk pregnancies are also associated with maternal anxiety. Potential adverse effects of antenatal CTGs

PowerPoint Presentation:

This systematic review found no clear evidence that in high-risk pregnancies fetal assessment by antenatal CTG benefits either the mother or her fetus. Although antenatal CTG may not increase a woman’s chance of having a caesarean section, it does not prevent the risk of perinatal death either. WHO Reproductive Health Library ; Geneva: World Health Organization. Antenatal cardiotocography for fetal assessment: 1 July 2010).

PowerPoint Presentation:

-- The available evidence for the benefit of traditional antenatal CTG in high-risk pregnancies makes its difficult to recommend its use for fetal assessment. -- Moreover, the reduction of perinatal death associated with the use of computerized CTG was compromised by the low quality of the studies included in the review . Cont. -

Implications for research :

Implications for research Research on the effectiveness of traditional CTG should focus on women with specific conditions that pose risks to fetal health e.g the use of CTG for decreased fetal movements or at increased risk of stillbirth. the use of CTG in combination with other tests of fetal wellbeing should also be assessed. The use of computerised CTG should be evaluated as there is currently little high-quality evidence to support its use, but preliminary findings appear encouraging .



Considerations for which form of monitoring to use on admission:

Considerations for which form of monitoring to use on admission Has the woman had good antenatal care? Are you aware of the fetal welfare and development? Are there any risk factors present? Is the woman in labour?

Is the woman established in labour?:

Is the woman established in labour? The interpretation of the FHR pattern should be considered in context.

PowerPoint Presentation:

Once a woman is in established labor, intermittent auscultation of the fetal heart after a contraction should be started in low risk pregnancy. .

Practice Recommendations for intermittent auscultation:

Practice Recommendations for intermittent auscultation Healthy women with uncomplicated labour IA with Pinards /Doppler recommended. Active labour - after contraction for at least 60 seconds & at least -- every 15mins 1 st stage -- every 5mins 2 nd stage

Who should have continuous electronic FHR monitoring?:

Who should have continuous electronic FHR monitoring? Antenatal risk factors Prematurity Post term Pre- eclampsia / eclampsia Diabetes Fetal Growth restriction Non-reassuring antenatal fetal welfare assessment Multiple pregnancy Malpresentation

Who should be have continuous electronic FHR monitoring?:

Who should be have continuous electronic FHR monitoring? Intrapartum factors Syntocinon : oxytocin use for augmentation Meconium : significant meconium-stained liquor, and considered for light meconium-stained liquor Epidural Suspicious FHR / abnormal FHR detected by intermittent auscultation Prolonged rupture of the membranes Prematurity Previous C/S maternal pyrexia fresh bleeding developing in labour

Meta analysis of RCTs of Intrapartum CTG monitoring:

Meta analysis of RCTs of Intrapartum CTG monitoring 12 Trials (as of 2008) In 10 centres in the US, Australia, Europe and Africa 58,855 women and 59,324 babies Both high and low risk pregnancies Compared routine EFM with intermittent auscultation

Meta analysis Results:

Meta analysis Results A significant decrease in : Rate of 1 minute Apgar scores less than 4 (RR = 0.82 and CI 0.65 - 0.98) Neonatal seizures (RR=0.50 and CI 0.32 - 0.82)

Meta analysis Results:

Meta analysis Results A significant increase in: -- CS rates ( 1.41%rr) . -- Operative vaginal delivery (RR=1.23)

Meta analysis Results:

Meta analysis Results No effect on: R ate of 1 min Apgar scores <7 R ate of admissions to NICU Perinatal death rate 5 min Apgar scores Cerebral palsy rate

Why we care about electronic FHR monitoring?:

Why we care about electronic FHR monitoring? Use of EFM increased overall cesarean rate (OR- 1.53, CI 1.17-2.01) compared to intermittent auscultation Use of EFM increased vacuum (OR – 1.23, CI 1.02-1.49) and forceps deliveries (OR – 2.4, CI 1.97-3.18) Use of EFM did NOT reduce overall perinatal mortality (OR – 0.87, CI 0.57-1.33 ) ACOG Practice Bulletin #70; 2005

Why care about electronic FHR monitoring?:

Why care about electronic FHR monitoring? Incorporated into clinical practice without confirmatory research evidence Continued use in clinical practice despite lack of benefit proven in later research 45

PowerPoint Presentation:

“ Continuous electronic fetal monitoring (CEFM) was introduced with an aim of reducing perinatal mortality and cerebral palsy. This reduction has NOT been demonstrated in the systematic reviews of RCTs; however an increase in maternal intervention rates (cesarean and operative vaginal deliveries) has been shown.” – RCOG Why care about electronic FHR monitoring?

Why care about electronic FHR monitoring?:

Why care about electronic FHR monitoring? Bottom line: We care because the community standard and malpractice lawyers insist we care. 47

Take Home Pearls:

48 Take Home Pearls CEFM shown to increase operative deliveries without reducing perinatal death or cerebral palsy Standard terminology is recommended to help standardize communication;so that everybody speaks the same language

Take Home Pearls:

CTG’s are a screening test Sensitivity - If the FHR pattern is reassuring then you can be reassured of fetal welfare Specificity - If the FHR pattern has non-reassuring features it is difficult to fully assess fetal welfare without performing another test. Take Home Pearls

Take Home Pearls:

50 Take Home Pearls CEFM is mandatory in high risk groups , in labor but ???? Antenatally Antenatally – U/Sound + Doppler studies Intrapartum – Fetal scalp blood sampling

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