Journals / Muğla Sıtkı Koçman Üniversitesi Tıp Dergisi / 2026 / Volume: 13 Issue: 2

Interobserver And Intraobserver Reliability of NICHD Three-tier Fetal Heart Rate Interpretation at Term Delivery

Term Doğumlarda NICHD Üçlü Fetal Kalp Hızı Yorumlamasının Gözlemciler Arası ve Gözlemci İçi Güvenilirliği

Didar Kurt(UNIVERSITY OF HEALTH SCIENCES, İSTANBUL KARTAL DR. LÜTFİ KIRDAR HEALTH RESEARCH CENTER, DEPARTMENT OF SURGICAL MEDICAL SCIENCES, DEPARTMENT OF OBSTETRICS AND GYNAECOLOGY)0009-0008-1463-0157
Aylin Yılmaz(UNIVERSITY OF HEALTH SCIENCES, İSTANBUL KARTAL DR. LÜTFİ KIRDAR HEALTH RESEARCH CENTER, DEPARTMENT OF SURGICAL MEDICAL SCIENCES, DEPARTMENT OF OBSTETRICS AND GYNAECOLOGY)0000-0001-6243-3993
Pages
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Publication Date
2026-08-27
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AI Summary & Key Takeaways

AI Insight
⚡ TL;DR(Too Long; Didn't Read)

In conclusion, fetal heart rate interpretation immediately before delivery demonstrates variable reproducibility across CTG components.

📌 3 Key Takeaways

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Objective & Hypothesis:The aim of this study was to evaluate interobserver and intraobserver agreement in the interpretation of fetal heart rate tracings obtained immediately before delivery at term using the National Institute of Child Health and Human Development (NICHD) three-tier fetal heart rate classification system and to assess agreement among individual cardiotocography (CTG) subparameters.
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Key Findings & Data:This retrospective study included pregnancies at ≥37 weeks of gestation that were delivered at a tertiary center.
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Conclusion & Impact:In conclusion, fetal heart rate interpretation immediately before delivery demonstrates variable reproducibility across CTG components.
🔬Design:Review & Systematic Survey
📍Scope:Comprehensive Sample
⚙️Variables:Cardiotocography · Fetal heart rate monitoring · Kappa statistics

Abstract

The aim of this study was to evaluate interobserver and intraobserver agreement in the interpretation of fetal heart rate tracings obtained immediately before delivery at term using the National Institute of Child Health and Human Development (NICHD) three-tier fetal heart rate classification system and to assess agreement among individual cardiotocography (CTG) subparameters. This retrospective study included pregnancies at ≥37 weeks of gestation that were delivered at a tertiary center. Fetal heart rate tracings obtained immediately before delivery, including antepartum non-stress test recordings before elective cesarean delivery and intrapartum CTG recordings during labor or emergency cesarean delivery for suspected fetal distress, were independently reviewed by two blinded perinatology specialists. Intraobserver reliability was assessed after a 2–4-week interval. Interobserver and intraobserver agreement were evaluated using Cohen’s kappa, quadratic weighted kappa, percent agreement, and 95% confidence intervals. A total of 113 tracings were analyzed. Baseline fetal heart rate category demonstrated high percent agreement (97.3%) but near-zero kappa, consistent with a prevalence-related kappa paradox. Baseline variability (weighted κ=0.56) and acceleration presence (κ=0.53) demonstrated moderate agreement, whereas pathologic deceleration type showed substantial agreement (weighted κ=0.72), representing the most reproducible parameter. In conclusion, fetal heart rate interpretation immediately before delivery demonstrates variable reproducibility across CTG components. Pathologic decelerations are the most reliably interpreted features, whereas physiologic parameters showed only moderate agreement. These findings support the use of cardiotocography within a broader clinical context and highlight the need for prospective studies integrating observer reliability with neonatal outcomes.

Özet

Bu çalışmanın amacı, term gebeliklerde doğum öncesinde elde edilen fetal kalp hızı kayıtlarının Ulusal Çocuk Sağlığı ve İnsan Gelişimi Enstitüsü (National Institute of Child Health and Human Development, NICHD) üçlü fetal kalp hızı sınıflama sistemi kullanılarak yorumlanmasında gözlemciler arası ve gözlemci içi uyumu değerlendirmek ve kardiyotokografi (KTG) alt parametreleri arasındaki uyumu incelemektir. Bu retrospektif çalışmaya üçüncü basamak merkezde ≥37 gebelik haftasında doğum yapan gebeler dahil edildi. Doğumdan hemen önce elde edilen fetal kalp hızı kayıtları; elektif sezaryen öncesi antepartum non-stres test kayıtları ile travay sırasında veya fetal distres şüphesi nedeniyle acil sezaryen öncesinde alınan intrapartum KTG kayıtlarından oluştu. Kayıtlar, klinik bilgilere kör iki perinatoloji uzmanı tarafından bağımsız olarak değerlendirildi. Gözlemci içi güvenilirlik 2–4 haftalık arayla yeniden değerlendirme yapılarak analiz edildi. Gözlemciler arası ve gözlemci içi uyum Cohen kappa, kuadratik ağırlıklı kappa, yüzde uyum oranı ve %95 güven aralığı kullanılarak değerlendirildi. Toplam 113 fetal kalp hızı kaydı analiz edildi. Bazal fetal kalp hızı kategorisi yüksek yüzde uyum (%97.3) göstermesine rağmen prevalansa bağlı kappa paradoksu ile uyumlu şekilde kappa değeri sıfıra yakın bulundu. Bazal varyabilite (ağırlıklı κ=0.56) ve akselerasyon varlığı (κ=0.53) orta düzeyde uyum gösterdi. Patolojik deselerasyon tipi ise yüksek düzeyde uyum (ağırlıklı κ=0.72) göstererek en güvenilir parametreydi. Sonuç olarak, doğum öncesi fetal kalp hızı yorumlamasında KTG bileşenleri arasında değişken düzeylerde tekrarlanabilirlik bulunmaktadır. Patolojik deselerasyonlar en güvenilir yorumlanan bulgular iken, fizyolojik parametrelerde orta düzeyde uyum izlenmiştir. Bu bulgular, kardiyotokografinin daha geniş klinik bağlam içerisinde değerlendirilmesi gerektiğini ve gözlemci güvenilirliği ile neonatal sonuçları birlikte inceleyen ileri prospektif çalışmalara ihtiyaç olduğunu göstermektedir.

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Cite This Article

Kurt, D., Yılmaz, A. (2026). Interobserver And Intraobserver Reliability of NICHD Three-tier Fetal Heart Rate Interpretation at Term Delivery. Muğla Sıtkı Koçman Üniversitesi Tıp Dergisi, Volume: 13 Issue: 2. https://doi.org/10.47572/muskutd.1954985

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