Kardiotografiya (CTG) - is a method to fix the fetal heart rate and uterine contractions using ultrasound.As a rule, CTG carried out during pregnancy in the third trimester.In the earlier timing of the application of this method it is practically useless.The device, which is used in this procedure, called a CTG or fetal monitor.
What CTG during pregnancy
CTG method allows you to record your heart rate (HR) of the fetus and uterine contractions simultaneously, using two transmitters.Transmitters are both internal and external;last used more often.
For outdoor use CTG external sensors, which are arranged, respectively, on the surface of the abdomen.One of the transmitters - tokodinamometr - registers tension of the abdominal wall mothers, thereby reducing estimated uterus.The other transmitter is approximately over the heart of the child, and it measures the heart rate.If
conduct internal CTG sensors using a catheter is inserted through the vagina - this procedure provides more accurate
In both cases, the registration of uterine contractions and fetal heart rate using an ultrasound - a high frequency sound that people can not hear.He passes freely through fluids and soft tissues, but is reflected (like an echo) when faced with a hard surface.For example, it can easily pass through the blood and heart chambers, but the valves, which consist of denser tissue, its delay, so that a considerable part of ultrasound is reflected.Another example: ultrasound passes easily through the bile in the gall bladder Gall bladder: structure and function , but if it is "stumble" on a stone, get a strong echo.
CTG method is based on the Doppler effect, which is that the ultrasonic waves are reflected at a different frequency from the moving and stationary objects.
What does the CTG during pregnancy
The fetal heart rate in the third trimester of pregnancy is beating at a rate of 110 to 160 beats per minute.This is significantly higher than that of adults who have a normal heart rate - between sixty and one hundred beats per minute.
fetal heart rate of 100 to 109 or from 161 to 180 is not considered abnormal, although sometimes can point to certain health problems.Abnormal fetal heart rate - below 100 or above 180 beats per minute.
addition, estimated indicators such as heart rate variability - a deviation from the average heart rate.The normal variation ranges from 5 to 20-25 beats per minute during the measurement.If it is too low, it may indicate the following problems:
- hypoxia and acidosis.The lack of oxygen and increased acidity can cause fetal organism to inhibition of its nervous system;
- taking drugs or anesthetics.Usually, the variability becomes normal when the drugs are completely eliminated from the body.
In addition, heart rate variability may be low, when the baby sleeps.
Causes for CTG can be:
- Vaginal bleeding during pregnancy;
- Premature onset of labor;
- High blood pressure Blood pressure - dangerous if his swing? mother;
- mismatch size and gestational age of the fetus;
- identified during ultrasound signs of abnormalities in the fetus;
- rupture of membranes, and then for several hours deliveries have not begun;
- Reduced heart rate of the fetus revealed in other surveys;
- Abnormal color of amniotic fluid;
- Supplementation during pregnancy, which can lead to uterine hyperstimulation and fetal distress.
CTG during pregnancy can also be administered to women who have already passed the expected delivery date and in cases where childbirth cause artificially using special drugs or when the anesthesia used during labor epidural.
How to prepare
As for CTG anesthesia is not used specifically to prepare for it is not necessary.You can eat a couple of hours before the procedure - it does not affect the results.You should not eat too much, because in the course of the CTG will you lie down or recline, with the result that after a hearty meal can happen attack of heartburn Heartburn - no cause for concern? (pregnant women suffer from it often enough).
recommended before starting to empty the bladder CTG The bladder - structure and function ;in late pregnancy urination happen often, and it's better if you do not have to interrupt the process in order to go to the toilet.
How does the CTG during pregnancy
In most cases, CTG carried out externally.
- During this procedure around the mother's abdomen fix a wide belt of elastic fabric, which is attached to two round plate with a diameter approximately equal to the diameter of a tennis meat.The signal was stronger, the physician typically first applied to the skin gel.
- belt connected to kotografom, which interprets the signals received from transmitters.At the same time, and the doctor and the patient can hear the baby's heartbeat.
- If CTG carried out before the onset of labor, the patient may be asked to press a special button every time she feels the baby move.
Outside CTG is completely painless for the patient.When is an internal KGG, the patient may feel some discomfort at the time of insertion and removal of the catheter, but it should not feel pain.
The patient can go home immediately after the procedure, of course, except for those cases where the CTG held during childbirth.
Overall, CTG is harmless for both the woman and the fetus - so far there was no evidence of any harmful side effects associated with the survey of pregnant women with ultrasound.