Quantitative Cardiotocography and Doppler Ultrasound in the Detection of Hypoxia among Late-onset FGR

Authors

  • Teodora Yordanova-Ignatova Medical University of Sofia and Orthogyn Medical and Dental Center, Bulgaria
  • Constantsa Neykova University Obstetrics and Gynecology Hospital “Maichin Dom”, Bulgaria
  • Peter N. Ignatov Medical University of Sofia and Orthogyn Medical and Dental Center, Bulgaria

DOI:

https://doi.org/10.7546/CRABS.2024.11.14

Keywords:

quantitative cardiotocography, CTG, computerized CTG, Doppler, late-onset FGR, hypoxia, fetal monitoring

Abstract

The aim of this paper was to evaluate the benefits of combining Doppler measurements of placental/fetal blood vessels with computerized cardiotocography (quantitative cardiotocogrpahy – qCTG) in the detection of fetal hypoxia (pH < 7.20) among late-onset growth restricted (FGR) fetuses.

This is a retrospective observational study, including 356 singleton pregnancies diagnosed with late-onset fetal growth restriction (FGR). The trial was undertaken between 2018 and 2021 in Second Municipal Hospital for Obstetrics and Gynecology Sheynovo, which is a tertiary referral facility, located in Sofia, Bulgaria. Women participating in the study underwent serial cardiotocographic and Doppler examinations of umbilical artery (UA), middle cerebral artery (MCA), and ductus venosus (DV). The cerebro-placental ratio (CPR) was also calculated. Analysis of cardiotocographic findings was performed by standard CTG and the “quantitative cardiotocogrpahy” (qCTG) computer algorithm. Relationships between antenatal test results and cord artery pH < 7.20 were analysed using logistic regression.

Three hundred and fourteen participants (88.2%) met the inclusion criteria. Logistic regression demonstrated that abnormalities in qCTG readings, CPR and DV Doppler velocimetry were independently correlated with the occurrence of fetal hypoxia (pH < 7.20) in the newborn. The model obtained after elimination of variables that did not prove to be significantly correlated with the dependent variable (UA, P = 0.0882; MCA, P = 0.0592; Standard CTG, P = 0.1738) allowed the identification of neonatal hypoxia with 86.1% sensitivity and 79.5% specificity (AUC = 0.835, P <0.0001). Furthermore, according to the equation derived from this final regression model, the probability of fetal hypoxia varies between a minimum of 6%, when none of the significant risk factors (DV, CPR and qCTG) are seen, to a maximum of 97% when all of them are being manifested.

This is the first study to incorporate qCTG in fetal assessment of late-onset growth restriction. It demonstrates that unlike standard cardiotocography, qCTG alone correlates strongly with hypoxia (pH < 7.20) at birth.

We are proposing a new diagnostic algorithm, called QDSP Protocol (Quantitative cardiotocography and Doppler Surveillance of Pregnancy), based on the combined use of qCTG, CPR and DV Doppler, which seems to be more accurate in the detection of hypoxia (pH < 7.20) in late-onset FGR, compared to listed Doppler modalities and standard CTG.

The implementation of QDSP Protocol in clinical practice has the potential to reduce the number of unnecessary operative deliveries and lower the morbidity/mortality rates in late-onset FGR fetuses, although further prospective studies are needed to support these assumptions.

Author Biographies

Teodora Yordanova-Ignatova, Medical University of Sofia and Orthogyn Medical and Dental Center, Bulgaria

Mailing Address:
Medical University of Sofia,
15 Akad. Ivan Evstratiev Geshov Blvd,
1431 Sofia, Bulgaria
and
Orthogyn Medical and Dental Center,
2A Belmeken St, 1618 Sofia, Bulgaria

E-mail: yordanova@orthogyn.com

Constantsa Neykova, University Obstetrics and Gynecology Hospital “Maichin Dom”, Bulgaria

Mailing Address:
Department of High-risk Pregnancy,
University Obstetrics and Gynecology Hospital “Maichin dom”,
2 Zdrave St, 1463 Sofia, Bulgaria

E-mail: neykovaconstantsa@yahoo.com

Peter N. Ignatov, Medical University of Sofia and Orthogyn Medical and Dental Center, Bulgaria

Mailing Addresses:
Medical University of Sofia,
15 Akad. Ivan Evstratiev Geshov Blvd,
1431 Sofia, Bulgaria
and
Orthogyn Medical and Dental Center,
2A Belmeken St, 1618 Sofia, Bulgaria

E-mail: ignatov@orthogyn.com

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Published

30-11-2024

How to Cite

[1]
T. Yordanova-Ignatova, C. Neykova, and P. Ignatov, “Quantitative Cardiotocography and Doppler Ultrasound in the Detection of Hypoxia among Late-onset FGR”, C. R. Acad. Bulg. Sci., vol. 77, no. 11, pp. 1694–1704, Nov. 2024.

Issue

Section

Medicine