NEW POSSIBILITIES TO USE CARDIOTOCOGRAPHY TO ASSESS THE FETAL FUNCTIONAL STATE IN THE SECOND TRIMESTER OF PREGNANCY

Problem statement

Cardiotocography (CTG) is the most common method of instrumental monitoring of the fetal condition. Currently, the full potential of CTG is not utilized because the interpretation and computer analysis of data are possible at a minimum of 24 weeks but are implemented in practice only from 32 weeks of gestation. It is known that the second trimester of pregnancy is partially overlooked for the assessment of fetal well-being. The aim of this study was to identify characteristic cardiotocographic parameters in the second trimester of pregnancy. Research objectives: Establish the peculiarities of cardiotocography parameters in the second trimester of women with physiological pregnancy. Compare the cardiotocography data in the third and second trimesters of these women.

Methods

The assessment of fetal functional state was performed from 16 weeks of gestation until delivery, every 7-14 days, using the General Meditech CTG device equipped with ultrasound transducers operating at frequencies of 1.5 and 2.0 MHz, which are safe for use during pregnancy. The transducer was placed at the optimal point for auscultation of the fetal heart rate, considering the gestational age. Cardiotocograms were recorded for a minimum of 20 minutes. Up to 24 weeks of gestation, the optimal position for the woman was lying on her back and after 24 weeks, the lateral position was preferred. A total of 904 cardiotocograms were analyzed.

Results

The lowest values of CTG parameters related to variability (STV, LTV, EVP, amplitude, and frequency of variability) were observed at 16-19 weeks of gestation, with an increase in variability observed with advancing gestational age.

Conclusion

The established parameters of cardiotocography, characteristic of fetal physiological condition from 16 to 28 weeks of pregnancy, allow for a fundamental change in the functional diagnosis of the antenatal period of fetal life. Further research in this direction will be continued.

Key words: cardiotocography, STV, LTV, variability

References: RS. Zamaleeva, NA Cherepanova, AV Frizina, EY Yupatov , DV Frizin. Prediction of pla-cental pathology during the second trimester of pregnancy using a new risk assessment scale and fetal cardiotocography. Vopr. ginekol. akus. perinatol. (Gynecology, Obstetrics and Perinatology). 2020;19(5):36-43. DOI: 10.20953/ 1726-1678-2020-5-36-43