CARDIOTOCOGRAPH
MUHAMMAD ISHAQUE 208-2023
What is a
Cardiotocograph
(CTG)?
Electronic device
A cardiotocograph is an electronic device used
extensively in obstetrics to continuously monitor the
fetal heart rate (FHR) and uterine contractions
during pregnancy and labor. This provides a detailed
assessment of the baby's well-being.
Critical Tool
The CTG is a critical tool used by healthcare
providers to assess fetal well-being during both the
antenatal period (pregnancy) and labor. It helps to
identify potential signs of fetal distress, allowing for
timely interventions and better management of the
delivery process.
Indication of ETG
. Alterations in fetal HR present during auscultation
. High risk delivery like polyhydramnios, pre eclampsia, eclampsia
. induced labor
. If there is twin pregnancy
. Previous still birth
. History of fetal distress in prior pregnancies
Contraindications of CTG
. Uterine hemorrhage of unknown cause
. Placenta previa, it may also be associated with small risk of fetal injury
. Vaginal infection
. Uterine perforation
How CTG Works
Transducers Ultrasound Uterine Real-time
Contractions Information
The device employs One transducer
two transducers, uses ultrasound The second The CTG provides
which are technology and transducer is pressure real-time graphic and
strategically placed doppler effect to sensitive contraction numeric information,
on the mother's precisely measure tocodynamometer(St enabling healthcare
abdomen to capture the fetal heart rate, retch gauge) that providers to make
vital data. The patient typically ranging measures the informed decisions
should be laying from 110 to 150 pressure required to and respond promptly
comfortably in a left beats per minute, flatten a section of to any concerning
lateral or semi- and measures the abdominal wall this indicators
recumbent position interval between correlates with
to avoid maternal successive beats internal uterine
vena cava which indicates the pressure and
compression baby's condition. indicates any uterine
contractions
Types of
Cardiotocography
External Internal
Monitoring Monitoring
Uses non-invasive Involves the use of a
ultrasound transducers direct fetal scalp
placed on the mother's electrode (FSE) for
abdomen to monitor more accurate fetal
fetal heart rate and heart rate monitoring,
uterine contractions. typically employed
This method is suitable when membranes have
for antepartum and ruptured and a more
intrapartum monitoring, precise assessment is
providing a continuous required. This method
or intermittent provides a clearer
assessment of fetal signal, less susceptible
well-being without the to maternal
need for membrane movements, but carries
rupture. a slightly increased risk
of infection.
Allows continuous or intermittent fetal monitoring,
adapting to various clinical needs and patient conditions.
Key Measurements and Indicators
Baseline Fetal Heart Rate
Refers to the average fetal heart rate over a specified period, typically
measured in beats per minute (bpm). Normal baseline values usually range
1 between 110 and 160 bpm and it is best determined over a period of 5-10
minutes and the rate falls with advancing gestational age as a result of
maturing fetal parasympathetic tone and prior to term. Deviations from this
range may indicate fetal distress or other complications.
Baseline variability
The longer term fluctuation in heart rate occurring between 2 and 6 per
minute normal baseline variability reflects a normal fetal ANS and it is
2 considered abnormal when it is less than 10 bpm it is modified with fetal sleep
states (20-30 minutes) and hypoxia and fetal infections.
Fetal heart rate accelerations and decelerations
Increase in baseline fetal heart rate of at least 15 bpm lasting for 15 sec.
presence of two or more accelerations on 20-30min antepartum fetal CTG
3 indicates non hypoxic fetus
Fetal decelerations reduction in fetal heart rate of 15bpm or more lasting 15
sec or more they may indicate fetal hypoxia and umbilical cord compression
Uterine Contraction Frequency
Indicates how often uterine contractions occur during labor. The frequency is
4 typically measured from the beginning of one contraction to the beginning of
the next. Monitoring contraction frequency helps assess the progress of labor
and the potential impact on the fetus.
Identifies potential signs of fetal distress.
Clinical Applications
1 Antepartum Monitoring
Fetal monitoring before labor begins, especially in cases of maternal diabetes,
hypertension, or previous stillbirth. This allows healthcare providers to assess fetal
well-being and make informed decisions regarding the timing and mode of
delivery.
2 Intrapartum Monitoring
Continuous or intermittent fetal monitoring during labor to detect any signs of
fetal distress. This helps in managing labor progress and determining the need for
interventions such as assisted delivery or cesarean section.
3 Risk Assessment
Used for high-risk pregnancies with conditions such as preeclampsia, multiple
gestations, or intrauterine growth restriction (IUGR). CTG aids in evaluating fetal
reserve and placental function, optimizing outcomes for both mother and baby.
CTG monitoring plays a critical role in guiding medical interventions during childbirth,
including decisions related to oxygen administration, medication adjustments, and the need
for operative delivery to ensure fetal well-being and prevent potential complications.
