Cardiotocography (CTG) is prescribed late in pregnancy. It is held every two to three weeks, and sometimes more often. The procedure allows you to determine whether the child is good in the mother's belly, and the woman herself can decipher the data.
How is CTG
Cardiotocography is absolutely safe for both mother and child. The study is carried out using sensitive sensors that can decipher the baby's heartbeat and the contractions of the mother's uterus. Usually, CTG is prescribed after 26 weeks of pregnancy, since the data are too ambiguous at earlier stages. In some clinics, it is possible to check pregnant women every week, in others, this test is prescribed only twice.
The procedure looks like this: a pregnant woman lies down on a couch or sits in a chair, two sensors are attached to the stomach. One is in the area of the uterine contraction node, and the other is where the fetal heart is best heard. It is they who send the data to the electronic unit. CTG can be carried out on special equipment or using an ordinary computer - in any case, the device displays all the information on a printed sheet.
On the printout, you can see a graph of the baby's heartbeat, uterine contractions and the calculated indicators, on the basis of which conclusions are drawn about the condition of the child. Each indicator is evaluated in points: 0 if there are pronounced signs of fetal suffering, 1 if there are some signs of violations, and 2 if everything is in order.
Basal heart rate (HR or HR)
The basal rhythm is calculated between contractions and movements, it shows how the baby's heart rate is at rest. The range of 110-170 beats per minute is assessed as normal, 100-109 or 171-180 beats already indicates minor violations, but if the rhythm is below 100 or above 180 - the situation is already considered threatening, 0 points are given.
Heart rate variability of a child
Variability shows how much the rhythm deviates during contractions or movements of the child, while the frequency and height of the oscillations (hills and valleys on the graph) are assessed. If, on average, oscillations occur about 6 times per minute, their amplitude is from 10 to 25 beats - that's two points, everything is in order. It is alarming if the amplitude is 5-9 beats / min or more than 25 beats, with a frequency of less than 6 episodes. Fetal distress is evidenced by rare (up to 3 episodes per minute) oscillations, with an amplitude of only 5 beats / min.
Acceleration
Accelerations look like high teeth on the graph, more than 5 per minute is considered the norm. If there are less than 4 of them, the situation is considered unfavorable, the absence indicates a serious condition of the fetus and is estimated at 0 points. It should be noted that in practice, a small number of accelerations may indicate that the child is simply asleep and does not want to move, so it is better to repeat the study later.
Deceleration
Decelerations are decelerations of the heart rate rhythm and look like depressions on the graph. If they were registered in the first 5-10 minutes or were absent altogether, the child feels great. If decelerations appear after 15-20 minutes of recording, they are repeated, 1 point is given. Fetal distress is indicated by the variety and the large number of depressions on the graph.
CTG results
The scores for each indicator are summed up and evaluated by the doctor. 10-8 points (according to another classification 12-9) indicate a favorable state of the fetus. 7-5 points should cause alarm, more thorough research is required, the course of labor and the baby's condition will be under special control. If the CTG of the fetus is less than 4 points, it is most likely in serious condition, urgent delivery by cesarean section is required.
It should be noted that the results of CTG, like any other study, can be influenced by various factors. The child may be asleep or in an agitated state (for example, some children like to jump at certain times of the day or after their mother eats food), finally, the technique may be faulty. Therefore, before making important decisions, it is imperative to conduct a second examination.
