Cardiotocography (CTG)

Cardiotocography for Pregnancy

Cardiotocography (CTG) is a medical test used during pregnancy to monitor the baby's heart rate and the mother's contractions. It helps ensure the baby's well-being and can detect any problems early.

During the test, two sensors are placed on the mother’s belly. One sensor records the baby’s heartbeat, while the other tracks uterine contractions. The test usually takes about 20 to 40 minutes and is painless.

CTG is especially important in the later stages of pregnancy or if there are concerns about the baby’s health. It helps doctors understand how well the baby is coping with the stress of contractions and labor.

If the heart rate shows signs of distress, doctors can take action to ensure the baby’s safety. Overall, CTG is a valuable tool that provides important information about the health of both the mother and the baby during pregnancy.

Components of Cardiotocography

Cardiotocography (CTG) is a fetal heart rate (FHR) monitor consisting of a transducer placed on the mother’s abdomen.

Baseline FHR: Average fetal heart rate in the neighboring 10 minutes without any accelerations and decelerations: 110-160 bpm normal; < 110 bpm bradycardia; > 160 bpm tachycardia..

FHR Variability: Fluctuations of the baseline FHR give us an indication of the integrity of the fetal autonomic nervous system: absent (<0 bpm), minimal (≤5 bpm), moderate (6-25 bpm: reassuring), and marked (>25 bpm).

Accelerations: This refers to an increase in FHR of 15 bpm lasting for 15 seconds, considered to be the best indicator of fetal well-being. 

Decelerations: Decreases in FHR amplitude are called early decelerations, indicative of head compression; variable decelerations correspond to cord compression; late decelerations indicate uteroplacental insufficiency.

Uterine contractions: The hourly frequency, as well as contraction duration and intensity were recorded.

Cardiotocographic interpretations call for a reassurance component, suspicious symptomatology, or pathological perforations based on the amplitude of variability, presence of accelerations, and absence of concerning deceleration.

Advantages Of Cardiotocography (CTG)

CTG enjoys numerous advantages in obstetric care and the monitoring of fetal well-being. Here is a summary of some of the advantages:

• Non-invasive: It is non-invasive, safe for both mother and fetus, and requires no surgical incisions.

• Continuous CTG monitors: Monitoring fetal heart rate and contractions to allow immediate detection of deviations from normal well-being.

• Detection of Fetal Distress: Early Signals of distress, such as hypoxia, are detected by analyzing the fetal heart rate, and CTG allows an intervention to be done in a timely way to avert complications.

• Assessment of fetal well-being during labor: CTG assesses the fetal well-being in high-risk pregnancies and during complications of labor.

• Aids Clinical Decision Making: The information obtained by CTG acts indeed as a guide to the healthcare decision-making procedures during pregnancy and labor toward intervention options. 

• Wide Availability and Access: CTG machines are common in hospitals and maternity units, and thus the monitoring benefit is largely available for many pregnant women. 

• Records: The CTG provides a valid written record for future reference and legal purposes.

• Helpful in high-risk pregnancies: CTG monitoring is essential for high-risk pregnancy management.

Cardiotocography (CTG) Limitations

Though CTG has its benefits, there are limitations to this method:

• High false-positive rates resulting in unnecessary interventions.

• Subjectivity leading to interpretation inconsistencies.

• Normal CTG does not guarantee a healthy baby as it has low predictability.

• Increased maternal anxiety because of continuous monitoring.

• Restricted maternal movement, though the latest systems minimize this.

• Technical problems, such as maternal obesity, affect CTG performance.

• Not very effective in identifying all forms of fetal distress.

CTG is only one component of monitoring fetal well-being and should always be interpreted in conjunction with other clinical information.