Combination of XGBoost Analysis and Rule-Based Method for Intrapartum Cardiotocograph Classification



The two major components of a cardiotocograph (CTG) are uterine contraction (UC) and fetal heart rate (FHR) signals. CTG has been widely used to monitor fetal well-being in the past 50 years. The guideline provided by the National Institute of Child Health and Human Development (NICHD) classifies CTG patterns into three categories (I, II, and III) in evaluating the status of a fetus. However, manual interpretation of CTG is time-consuming and is subjected to inter-personal bias.


In this study, we combined the rule-based method and eXtreme Gradient Boosting (XGBoost) analysis in classifying CTG patterns. Because of the persistent controversies about the Category II of NICHD, XGBoost analysis was used to classify it into IIa and IIb. A total of 68 pregnant women were enrolled in this study.


Three categories (I, II, and III) were consistent in both manual interpretation by clinicians and our algorithm across all categories, and the average Kappa was about 0.72. The probability of fetal distress (FD) was 28.8% and 71.2% in the categories IIa and IIb, respectively.


These findings show the proposed method has the potential to provide a clinical assistant tool to monitor fetal well-being and has high potential to be an assistive and warning system to reduce the burden of medical staff.

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The authors are grateful for the assistance and co-operation of all the patients and medical staff involved in the clinical test.


This study was supported by the Ministry of Science and Technology, Taiwan, under Grant MOST 107-2221-E-006 -240 -MY3 and MOST 108-2221-E-006 -231 -MY3.

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Correspondence to Yi-Chun Du.

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The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Ethical Approval

The experimental protocol was established, according to the ethical guidelines of the Helsinki Declaration and was approved by the Human Ethics Committee of National Cheng Kung University Hospital (IRB Number: A-ER-105-477).

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Written informed consent was obtained from individual or guardian participants.

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Kuo, PL., Yen, L.B., Du, YC. et al. Combination of XGBoost Analysis and Rule-Based Method for Intrapartum Cardiotocograph Classification. J. Med. Biol. Eng. (2021).

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  • Cardiotocograph (CTG)
  • National Institute of Child Health and Human Development (NICHD)
  • eXtreme Gradient Boosting (XGBoost)
  • Fetal Distress (FD)