Time-Dependent Association Between Cardiotocographic Features and Hypoxic-Ischemic Encephalopathy

Area of Science:

• Perinatal medicine
• Biomedical signal processing
• Neonatal neurology

Background:

• Neonatal hypoxic-ischemic encephalopathy (HIE) is a severe birth complication.
• Cardiotocography (CTG) monitors fetal heart rate (FHR) and uterine pressure (UP) to assess risk.
• Current CTG analysis methods do not account for its nonstationary nature or time-varying properties.

Purpose of the Study:

• To investigate the association between CTG features and HIE development.
• To determine if incorporating time to delivery (TTD) enhances these associations.
• To identify relevant CTG features for improved HIE risk prediction.

Main Methods:

• Analysis of 88 features from FHR and UP signals in 25,197 deliveries.
• Categorization of infants into HIE, acidosis, and healthy groups based on blood gas exams.
• Quantification of associations using normalized mutual information, considering TTD.

Main Results:

• All analyzed CTG features demonstrated variation with TTD.
• 40 out of 88 CTG features showed significant associations with HIE development.
• Accounting for TTD strengthened the association for 26 of these HIE-related features.

Conclusions:

• Many CTG features lack significant association with labor outcomes.
• Specific CTG features are strongly associated with HIE risk.
• Automated HIE prediction models should utilize time-varying CTG features and incorporate TTD for improved accuracy.