Cardiotocogram(Ctg)

CARDIOTOCOGRAM DR IMRAN KHAN SUPERVISER DR.AFIFUDDIN

Definition Cardiotocography (CTG) CTG is technical means of recording (-grahpy) the fetal heart beat (cardio-) and the uterine contraction (-toco-). The machine used to perform this monitoring is called a cardiotocograph. CTG monitoring is essentially the used of cardiotocograph for evaluation of fetal wellbeing in labour

Basic features and fetal heart rate pattern Fetal heart rate pattern has 4 recognizable features : 

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Baseline heart rate 110 – 160 Baseline variability 5 – 25 Acceleration Deceleration

Baseline FHR : the mean level of FHR when this is stable, excluding acceleration and deceleration. It is determined over period of 5 – 10 minutes and expressed in beats per minute (BPM).

Baseline variability : the minor fluctuation in baseline FHR occurring at 3 –  5 cycle per minute. It is measured by estimating the difference in beat per minutes between highest peak and the lowest trough of fluctuation in one minute segment of trace. It is consider to reduce if less 5

Acceleration : Acceleration : transient increase in FHR of 15 bpm or more and lasting 15 second or more. Deceleration : Deceleration : Transient episodes of slowing FHR below the baseline level level of more than 15bpm and lasting 15 second second or more

Classification Classificat ion of CTG and Intrapartum trace ( RCOG 2001) Classification

Definition

Normal

All four features fall into the category

Suspicious

A CTG whose features fall into one of the non reassuring categories and the remainder of the features are reassuring

Pathological

A CTG whose features fall into two or more non reassuring categories or one or more abnormal categories

Baseline

Variability

Deceleration

Acceleration

Reassuring

110 - 160

>5

None

Present

Non reassuring

100 – 109 161 - 180

< 5 for > 40min but < 90min

Early deceleration, Variable deceleration , Single prolonged deceleration up to 3 min

Pathological

< 100 > 180

< 5 for > 90 min

Atypical variable deceleration, late deceleration, single prolonged deceleration > 3min

Types of deceleration Early deceleration Late deceleration Variable deceleration Atypical deceleration Prolonged deceleration

Early deceleration : Uniform, repetitive, periodic slowing of FHR with onset early in the contraction and return to baseline at the end of contraction Late deceleration : Uniform repetitive periodic slowing of FHR with onset mid to end of contraction and nadir more than 20 second after the peak of contraction and ending after the contraction contraction Variable deceleration : variable, intermittent periodic slowing of FHR with rapid onset and recovery. Time relationships with contraction contraction cycle are variable and they may occur in i n isolation Prolonged deceleration : An abrupt decrease in FHR to level below baseline last atleast 60 –  90 seconds. These deceleration become pathological if they cross to contraction,i.e. greater than 3 minutes

Atypical variable : variable deceleration with any of following additional deceleration component :  loss of primary or secondary rise in baseline rate Slow return to baseline FHR after the end of contraction Prolonged secondary rise in baseline rate Biphasic deceleration Continuation of baseline rate at lower level 

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Sinusoidal pattern : A regular oscillation of baseline long term variability resembling a sine wave. This smooth, undulating pattern lasting at least 10 minutes, has a relatively fixed period of 3 – 5 cycle per minute and amplitude of 5 -15

Modes of fetal heart monitoring 

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Continuous CTG Intermittent CTG Internal / direct monitoring ( fetal scalp electrode ) Intermittent auscultation

INDICATION FOR CONTINUOUS CTG MONITORING Maternal condition

Fetal condition

Antenatal

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Hypertension Diabetes mellitus Antepartum hemorrhage Cardiac disease Severe anemia Hyperthyroidism Renal disease

Intrapartum • • •

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Vaginal bleeding Maternal pyrexia Chorioamnionitis Epidural / reginonal anesthesia

Labour •

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Previous ceaseran section Prolonged ROM Induced / augmented labour Uterine hyperstimulation

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Growth restricted fetus Oligohydramion Prematurity Rhesus isoimmunization Multiple pregnancy Breech Meconium stained liquor Post term pregnancy

Intermittent CTG monitoring ( 2Hourly ) For all other patient not listed above Internal or direct monitoring / Fetal scalp electrode Indication External tracing inadequate / poor quality for interpretation Monitoring 1st twin in twin pregnancy in labour Contraindication Face presentation Unknown presentation HIV seropositive / Hep B,C Suspected thrombocytopenia 

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Intermittent auscultation Auscultation of FHR at regular intervals for at least 60 second

It is equally as effective as continuous CTG monitoring for low risk women in labour. continuous EFM should be offered and recommended if; A)there is evidence on auscultation of a baseline 160bpm. B)there is evidence on auscultation of any decelerations. C)If any intrapartum risk facrors develop. Intermittent auscultation should be done; A)every 15-30min(throughout 15-30min(throughout and after contraction) in active first stage of labour. B)every 5 min in active second stage(throughout and after contraction)

RESPONSIBILITIES ASSOCIATED WITH EFM(electronic fetal monitoring) a)Reason, a)Reas on, benefits and limitation

should be explained to

patient b)The date, time on the machine should be correctly set. C)paper speed should be set at 1cm/min d)Traces should be labeled with mother’s name, date,time,RN.

E)Any intrapartum events that affect FHR should be recorded on the tracing, signed, date and time. F)Any member of staff who reviewed the CTG tracing should note their findings on tracing together with time ,date, signature and chop.

G)If CTG is suspicious/pathological, suspicious/pathological, staff and house officer should ; .inform medical officer OR specialist. .change maternal position –left lateral .Withhold oxytocin infusion if required .Vaginal examination

Causes of fetal heart rate bradycardia .fetal bradycardia bradycardia is define as a decrease in the baseline FHR to less than 100beats per minute

1.FETAL HYPOXIA; HYPOXIA; brady bradycardia cardia is a late sign of fetal hypoxia(a hypoxi a(a continual lack of oxygen) .The heart rate slow in response to a depression of heart muscle(myocardial)activity muscle(myocardial)activity caused by this continued decrease in needed oxygen.

2.MEDICATION;; Medication such as narcotics cause 2.MEDICATION bradycardia brady cardia by preventing receptors sites in the fetal heart muscle from accepting epinephrine, which works to increase heart rate.

3.EPIDURAL ;Causes vasodilation, which leads to

an increase in the incidence of maternal hypotension during labour which causes bradycardia indirectly due to reflex mechanism, a potential complication for regional anesthesia. 4.SYNTHETIC OXYTICIN(PITOCIN)may OXYTICIN(PITOCIN)may produced bradycardia bradyc ardia by causing causing hyperstimul hyperstimulation ation of the uterine muscle(myometrium),resulting in hypoxia. hypoxia . .

5.MATERNAL HYPOTENSION; supine hypotension syndrome caused by pressure of the uterus and its content on the inferior inf erior vena cava cava , when you lay on your back, results in decrease in maternal blood pressure

Causes of fetal heart rate tachycardia tachycardia is defined as being .Tachycardia; suspicious tachycardia between 161-180 whereas a pathological pattern is above 180. 1.FETAL HYPOXIA; Tachycardia may be early sign of hypoxia(fetall lack of adequate oxygen). hypoxia(feta 2.MEDICATION; Medication Medication used to prevent/stop premature labor such as terbutaline(sympathomimetic),have terbutaline(sympathomimetic),have a stimulating stimulati ng effect on the fetal heart, which increase the heart rate.

THANKS

3.PREMATURITY;Apremature baby has 3.PREMATURITY;Apremature an immature nervous system resulting in increased heart rate. 4.MATERNAL 4.MA TERNAL FEVER; Both the mothers’ and the baby’s metabolism is increase, which result in increase heart rate. 5.FETAL INFECTION;This may be an early sign of an intrauterine infection(a stress reaction to sepsis)prolonged sepsis)prolong ed ruptured of membrane may lead to maternal and fetal infection