Cardiotocographic monitoring: what it is, what it is used for and how it works

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Philippe Gloaguen
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Also called "non-stress test", the cardiotocographic monitoring it's a non-invasive examination which does not cause problems neither to the mother nor to the fetus and serves for the control of fetal well-being and evaluation of the contractile activity of the future mother.



Generally, this is done as a standard practice at the 40th week, that is, when the pregnancy comes to an end and, associated with examination and ultrasound, it is used to monitor the well-being of the mother and baby. It can be brought forward to the 27/28 week in case of need, on the evaluation of the treating gynecologist, to monitor any pathologies.



It is also a commonly used test before childbirth during the stage of labor.

Read also: The positions of childbirth
  • How is cardiotocographic monitoring carried out?
  • When you do,
  • How is it evaluated?
  • Cardiotocographic monitoring during labor.

How cardiotocographic monitoring is performed

«The examination is carried out by placing two probes (three in the case of gemelli) on the woman's belly, in correspondence with the uterus, and has two objectives: to monitor the heart rate of the fetus, recording its variations, and to evaluate the uterine contractions in a registration area of duration of at least 15 20-minute»Specific head of Obstetrics and Gynecology in Humanitas San Pio X.



Il monitoring it is performed on a cot or on reclining chairs in the hospital outpatient clinic or in the emergency room, it is performed by obstetricians and certified by a gynecologist. “This is an exam free and it is done only in case of need ».

When you make

Normally, this examination is carried out at the end of gestation, around 40 weeks of pregnancy, but it may be useful to do it from 27-28 weeks of pregnancy "in cases where it is necessary to monitor the fetal well-being or the contractile activity of the pregnant woman if she reports that she is having contractions and is at risk of preterm birth - continues the expert -. However, it may also be necessary to carry out it in other cases in which pregnancy pathologies are present, such as maternal hypertension, fetal growth retardation (fetal underdevelopment), a threat of preterm birth, or premature rupture of membranes ".

The exam is also performed in stage of labor always to assess fetal well-being at this time.



Read also: Contractions: how to recognize them

How is it evaluated

In general, the layout records the heart rate of the fetus «Whose normal range (ie the heart rate baseline) should be 120-160 beats per minute. But this frequency is not constant, so during the exam, accelerations of the fetal beat greater than the baseline of about 10 beats per minute must be recorded - he adds -. Then there may also be slight decelerations, but medium-severe or late variable decelerations must be excluded ».

Depending on the results, the gynecologist may decide to proceed with an early birth. There may be gods false positives, because «the interpretation of the trace of the cardiotocographic monitoring it is very complex: in addition to the result of the registration, in fact, it is also necessary to evaluate the clinical history of the future mother and complete it with the result of other instrumental tests, in particular obstetric ultrasound ».

Read also: Contractions in pregnancy

Less controversial is the monitoring of contractions: "They are physiological if present in a maximum number of five contractions in a day: if the pattern shows the presence of numerous contractions, the clinician may decide to start or modulate a tocolytic therapy, which aims to make the contractions ".

Cardiotocographic monitoring during labor

Cardiotocographic monitoring is also used before Natural childbirth, During the stage of labor to assess fetal well-being. In general, "the examination is used by the obstetrician or gynecologist to assess whether it is necessary to speed up the time of labor or even, in the case of a pathological or pathological not reassuring, to decide to carry out an urgent caesarean section".

In the case of monitoring in the labor phase, «the duration of the examination is longer and is repeated according to the clinical condition of the patient even at intervals of one hour (for a total of 20 minutes of examination approximately every hour). If the examination highlights risk variables, the gynecologist evaluates the possibility of carrying out it at shorter intervals or switching to the continuous monitoring. This is also our "philosophy": each case is carefully evaluated to always guarantee the safety of mother and child ».

Questions and answers

How is cardiotocographic monitoring done?

The examination is performed by placing two probes (three in the case of twins) on the woman's belly, in correspondence with the uterus, and has two objectives: to monitor the heart rate of the fetus, recording its variations, and to evaluate the uterine contractions in a recording lasting at least 15-20 minutes.

When is cardiotocographic monitoring performed?

This examination is carried out at the end of gestation, around 40 weeks of pregnancy, but it may be useful to do it from 27-28 weeks of pregnancy in cases where it is necessary to monitor the fetal well-being or the contractile activity of the pregnant woman if she reports of having contractions and being at risk for preterm labor. However, it may also be necessary to carry out it in other cases in which there are pathologies of pregnancy, such as maternal hypertension, etc. The examination is also performed in the phase of labor, always to evaluate the fetal well-being at this time.

How is cardiotocographic monitoring evaluated? 

The trace records the heart rate of the fetus whose normal range should be 120-160 beats per minute. But this frequency is not constant, which is why fetal heart rate accelerations greater than the baseline of about 10 beats per minute must be recorded during the exam. Then there may also be slight decelerations, but medium-severe or late variable decelerations must be excluded. Depending on the results, the gynecologist may decide to proceed with an early birth.

TAG:
  • ultrasound monitoring
  • give birth
  • labor
  • contractions
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