CTG & partogram

Done by : Areej AL-Hadidi

CTG cardiotocograph it is sometimes called electronic fetal monitoring (EFM)

• The cardiotocograph (CTG) is a continuous tracing of the fetal heart rate used to assess fetal wellbeing, together with an assessment of uterine activity.

• The CTG recording is obtained with the pregnant woman positioned comfortably in a left lateral or semi-recumbent position to avoid compression of the maternal vena cava.

• Two external transducers are placed on the mother’s abdomen, each attached with a belt.

• One transducer is a pressure-sensitive contraction tocodynometer (stretch gauge) that measures the pressure required to flatten a section of the abdominal wall. This correlates with the internal uterine pressure and indicates if there is any uterine activity (contractions). We put it against the fundus

• The second transducer uses ultrasound and the Doppler effect to detect motion of the fetal heart, and measures the interval between successive beats, thereby allowing a continuous assessment of fetal heart rate. We divide the fetus into 3 thirds and we put it against the nearest 1/3 to the head

• Recordings are then made for at least 30 minutes with the output from

the CTG machine producing two ‘lines’ traced onto a running piece of paper, one a tracing of fetal heart rate and a second a tracing of uterine activity.

• The mother may be given a button to press to record any fetal movements

that she has felt. • In addition, the CTG machine may record fetal movements detected via

the tocodynometer.

• Fetal cardiac behaviour is regulated through the autonomic nervous system and by vasomotor, chemoceptor and baroreceptor mechanisms.

• It depends on sympathetic and parasympathetic interactions

• Pathological events, such as fetal hypoxia, modify these signals and hence cardiac response including variation in heart rate patterns, which can be detected and recorded in the CTG

• The baseline fetal heart rate falls with

advancing gestational age . Why?? as a result of maturing fetal parasympathetic

tone and, prior to term, 160 bpm is taken

as the upper limit of normal.

• Features that are reported from a CTG to define normality and identify abnormality and potential concern for fetal wellbeing include the:

– Baseline rate.

– Baseline variability.

– Accelerations.

– Decelerations.

Interpretation of the CTG must be in the context of any risk factors, for example suspected FGR or fetal anemia, and all features must be considered in order to make a judgment about the likelihood of fetal compromise.

Baseline fetal heart rate:

• The normal fetal heart rate at term is 110–160 beats per minute (bpm).

• The baseline rate is best determined over a period of 5–10 minutes

• Fetal tachycardias can be associated with maternal or fetal infection, acute fetal hypoxia, fetal anemia and drugs such as adrenoceptor agonists

Baseline variability:

• fluctuations in heart rate occurring between two and six times per minute.

• 5-15 (may be up to 25) up and down

• Normal baseline variability reflects a normal fetal autonomic nervous system.

• Abnormality called sinusoidal rhythm / loss of beat to beat variability(when it is less than 10 bpm )

Cont,,

• baseline variability is modified by :

– fetal sleep states and activity

– gestational age

– hypoxia

– fetal infection

– Fetal distress

– Fetal anemia

– drugs suppressing the fetal central nervous system, such as opioids, and hypnotics (all of which reduce baseline variability).

• It is the first thing to be affected

As fetuses display deep sleep cycles of 90 minutes at a time, baseline variability may be normally reduced for this length of time, but should be preceded and followed by a period of normal baseline variability on the CTG trace. (babies should wake up when we move them)

During sleep HR will decrease as well , so reduced variability with high baseline is always a sign of concern

Fetal heart rate accelerations:

• These are increases in the baseline fetal heart rate of at least 15 bpm, lasting for at least 15 seconds. In both X &Y axes

• The presence of two or more accelerations on a 20–30minutes

Fetal heart rate decelerations:

• These are transient reductions in fetal heart rate of 15 bpm or more, lasting for more than 15 seconds.

• Decelerations can be indicative of fetal hypoxia or umbilical cord compression.

• There is a higher chance of fetal hypoxia being present if there are additional abnormal features such as reduced variability or baseline tachycardia

Cont ,,

• Early / type I / mirror image decelerations

– They occur as a result of contractions and head compression

– Benign but if persists >60 minutes (reassess) , >90 minutes (no adequate time to recover)

– Reassure the mother

• delayed/ late/ type II:

– fetal distress

• variable

– Contractions are different in relation ,size or duration

– Cord compression

– Just change the position of the mother

type II management:

• Positional changes (left lateral to decrease the IVC compression)

• Hydration with IV fluid

• Leg elevation to correct maternal hypotension

• Administer O2 at 8-10 L/min (face mask)

• Analgesics

• D/C oxytocin if infusing contractions compress blood flow

• If persists >30 minutes measure fetal blood pH

– If normal close monitoring

– Abnormal delivery

• use instruments if the condition allow (forceps not vacuum because it needs time )

• CS if the cervix isn't fully dilated

*Conditions in which early delivery or intervention is indicated : Late deceleration Loss of beat to beat variability

The best route for delivery is by CS

Dr C BRAVADO

• DR: define risks (Hx& PE)

• C: contractions (3-5 in 10 minutes ,each one last for 40-60 seconds)

• B RA :baseline rate

• V: variability – Moderate variability: normal (5-15) – <5 reduced – Marked variability : indication of hypoxia (we can’t determine a baseline zig zag )

• A: accelerations

• D : decelerations

• O: overall assessment

PARTOGRAM

• partogram is a composite graphical record of key data (maternal & fetal) during labour entered against time on a single sheet of paper.

component of partogram: Patient Identification

Time (recorded in 1hr intervals)

Fetal Heart Rate

State of Membranes

Cervical Dilatation

Uterine Contractions

Drugs & Fluids

BP (2 hours intervals)

Pulse Rate (30 minutes intervals)

Oxytocin

Urinalysis

Temperature

Cont,,

• The Alert line starts at 4 cm of cervical dilatation and it travels diagonally upwards to the point of expected full dilatation (10 cm) at the rate of 1 cm per hour.

• The action line is located 4 hours to the right of the alert line.

• As slope is to the left side of the alert line everything is ok

• Cervical dilatation represents the active phase

• Descent represents the second stage

• It is used for:

1.record observations

2.plan and adjust management guidelines

3. indicate the appropriate timing of certain interventions can be incorporated

• We remove the latent phase in the modified one . Why??

– Latent phase is difficult to diagnose and assign its start which lead to early admission and intervention

– Prolonged latent stage is relatively infrequent and doesn’t usually associated with poor perinatal outcomes