A CTG (cardiotocography) is a method of monitoring the fetal heart rate and uterine contractions during pregnancy and birth.

1. Purpose of CTG: The main purpose of a CTG is to record the fetal heart rate and correlate it with the mother’s uterine contractions. This helps to monitor the fetus’ response to labor and possible signs of stress or oxygen deprivation.
2. Recording the heart rate: The CTG records the fetal heart rate in beats per minute (bpm). A normal fetal heart rate is typically between 110 and 160 bpm. Deviations from this norm may indicate problems.
3. Recording the contractions: The CTG also records the mother’s uterine contractions. This helps to monitor the timing and duration of labor.
4. Interpretation of the CTG: The interpretation of CTGs is very dependent on the experience of the examiner. Even very experienced doctors can interpret the same CTGs very differently.

There are two main types of CTGs: analog CTGs and digital CTGs. Here are the differences between the two:

Analog CTG (paper CTG):

1. Paper recording: Analog CTG records the fetal heart rate and uterine contractions on a paper strip. This strip shows the information in real time, and doctors and obstetricians can visually monitor the heart rate and contractions.
2. Limited data analysis: With analog CTGs, data analysis is limited. Physicians can recognize patterns such as accelerated or decelerated heart rate, increased contractions or absence of heart rate changes, but interpretation is highly dependent on experience.
3. Archiving and storage: Analog CTG tapes can be stored in the patient file or as historical records, but are less compatible with digital archiving systems.

Digital CTG:

1. Electronic recording: Digital CTG uses electronic sensors to record the fetal heart rate and uterine contractions. The data is recorded in a digital format and displayed on a monitor.
2. Advanced data analysis: Digital CTGs offer advanced data analysis functions. The software can recognize patterns, trigger alarms and continuously monitor the heart rate. This can help to detect abnormalities more quickly and accurately.
3. Improved long-term monitoring: Digital CTGs enable continuous long-term monitoring and a comparison with previous examinations.

At our specialist prenatal practice, we set the standards of fetal monitoring at the highest level! We use our experience in Doppler sonography and the very best CTG equipment with STV (Short Time Variations) analysis and software, the so-called Oxford CTGs.

The Oxford CTG is also known as the Dawes-Redman analysis. It has CTG software that should provide more objective data in order to prevent prenatal misinterpretation of CTGs. It was developed at Oxford University over a period of 35 years. The method is based on the technology with the world’s largest database of CTGS and their outcomes. A so-called 100K algorithm contains over 100,000 CTG recordings and their outcomes. We regularly implement this worldwide objective computer analysis, filtered through our many years of clinical experience, in practice.
High-risk pregnancies such as those with growth restriction or pre-eclampsia benefit most from this.

Each Oxford CTG is classified as inconspicuous after all the criteria have been met. The following Dawes and Redman analysis criteria apply to all fetuses:

• Short-term variation ≥= 3 ms
• Heart rate between 110-160 HFR, with slightly higher or lower rates acceptable after 30 min if all other parameters are within normal range
• and other criteria…

The short-term variation (STV) is the most significant and important parameter in the Oxford CTG. It analyzes the mini-changes that cannot be identified by the human eye. The oscillation is determined over a very short period of time (up to 10 heartbeats). The short-term variations provide information about the blood flow to the fetal brain and therefore about the child’s well-being. This value is so reliable that it has been classified as the most important parameter for fatal monitoring in high-risk cases.

A Cochrane Review has already shown a significant reduction in the perinatal mortality rate when using a digital Oxford CTG compared to traditional CTG interpretation (Grivell et al., 2015). At the same time, no increased caesarean section rate was recorded thanks to the Oxford CTG.

By using the latest technology, we can provide much better support for our youngest patients and reassure their parents.

Your expert in prenatal diagnostics and high-risk pregnancy in Hamburg