{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,28]],"date-time":"2026-01-28T07:32:36Z","timestamp":1769585556675,"version":"3.49.0"},"reference-count":30,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,9,1]],"date-time":"2021-09-01T00:00:00Z","timestamp":1630454400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Pediatr."],"abstract":"<jats:p>Intrapartum fetal monitoring's primary goal is to avoid adverse perinatal outcomes related to hypoxia\/acidosis without increasing unnecessary interventions. Recently, a set of indices were proposed as new biomarkers to analyze heart rate (HR), termed HR fragmentation (HRF). In this work, the HRF indices were applied to intrapartum fetal heart rate (FHR) traces to evaluate fetal acidemia. The fragmentation method produces four indices: PIP-Percentage of inflection points; IALS-Inverse of the average length of acceleration\/deceleration segments; PSS-Percentage of short segments; PAS-Percentage of alternating segments. On the other hand, the symbolic approach studied the existence of different patterns of length four. We applied the measures to 246 selected FHR recordings sampled at 4 and 2 Hz, where 39 presented umbilical artery's pH \u2264 7.15. When applied to the 4 Hz FHR, the PIP, IASL, and PSS showed significantly higher values in the traces from acidemic fetuses. In comparison, the percentage of \u201cwords\u201d <jats:inline-formula><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" id=\"M1\"><mml:msubsup><mml:mrow><mml:mi>W<\/mml:mi><\/mml:mrow><mml:mrow><mml:mn>1<\/mml:mn><\/mml:mrow><mml:mrow><mml:mi>h<\/mml:mi><\/mml:mrow><\/mml:msubsup><\/mml:math><\/jats:inline-formula> and <jats:inline-formula><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" id=\"M2\"><mml:msubsup><mml:mrow><mml:mi>W<\/mml:mi><\/mml:mrow><mml:mrow><mml:mn>2<\/mml:mn><\/mml:mrow><mml:mrow><mml:mi>s<\/mml:mi><\/mml:mrow><\/mml:msubsup><\/mml:math><\/jats:inline-formula> showed lower values for those traces. Furthermore, when using the 2 Hz, only IASL, <jats:italic>W<\/jats:italic><jats:sub>0<\/jats:sub>, and <jats:inline-formula><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" id=\"M3\"><mml:msubsup><mml:mrow><mml:mi>W<\/mml:mi><\/mml:mrow><mml:mrow><mml:mn>2<\/mml:mn><\/mml:mrow><mml:mrow><mml:mi>m<\/mml:mi><\/mml:mrow><\/mml:msubsup><\/mml:math><\/jats:inline-formula> achieved significant differences between traces from both acidemic and normal fetuses. Notwithstanding, the ideal sampling frequency is yet to be established. The fragmentation indices correlated with Sisporto variability measures, especially short-term variability. Accordingly, the fragmentation indices seem to be able to detect pathological patterns in FHR tracings. These indices have the advantage of being suitable and straightforward to apply in real-time analysis. Future studies should combine these indexes with others used successfully to detect fetal hypoxia, improving the power of discrimination in a larger dataset.<\/jats:p>","DOI":"10.3389\/fped.2021.662101","type":"journal-article","created":{"date-parts":[[2021,9,4]],"date-time":"2021-09-04T02:13:13Z","timestamp":1630721593000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Fetal Heart Rate Fragmentation"],"prefix":"10.3389","volume":"9","author":[{"given":"Matilde","family":"Costa","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mariana","family":"Xavier","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"In\u00eas","family":"Nunes","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Teresa S.","family":"Henriques","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2021,9,1]]},"reference":[{"key":"B1","volume-title":"Fetal Heart Rate Monitoring","author":"Freeman","year":"2012"},{"key":"B2","doi-asserted-by":"publisher","first-page":"5","DOI":"10.1016\/j.ijgo.2015.06.018","article-title":"FIGO consensus guidelines on intrapartum fetal monitoring: physiology of fetal oxygenation and the main goals of intrapartum fetal monitoring","volume":"131","author":"Ayres-de Campos","year":"2015","journal-title":"Int J Gynecol Obstet"},{"key":"B3","doi-asserted-by":"publisher","first-page":"17","DOI":"10.1097\/00006254-199401000-00009","article-title":"Electronic fetal monitoring and later outcome","volume":"49","author":"Paneth","year":"1994","journal-title":"Obstet Gynecol Survey"},{"key":"B4","doi-asserted-by":"publisher","first-page":"978","DOI":"10.1111\/j.1471-0528.2011.03003.x","article-title":"Knowledge of adverse neonatal outcome alters clinicians' interpretation of the intrapartum cardiotocograph","volume":"118","author":"Ayres-de Campos","year":"2011","journal-title":"BJOG"},{"key":"B5","doi-asserted-by":"publisher","first-page":"536","DOI":"10.1080\/00016340802023053","article-title":"Interobserver agreement in the assessment of intrapartum automated fetal electrocardiography in singleton pregnancies","volume":"87","author":"Ojala","year":"2008","journal-title":"Acta Obstet Gynecol Scand"},{"key":"B6","doi-asserted-by":"publisher","first-page":"1202","DOI":"10.1111\/j.1471-0528.2007.01480.x","article-title":"Review of the first 1502 cases of ECG-ST waveform analysis during labour in a teaching hospital","volume":"114","author":"Doria","year":"2007","journal-title":"BJOG"},{"key":"B7","doi-asserted-by":"publisher","first-page":"524","DOI":"10.1016\/0002-9378(85)90619-2","article-title":"The Dublin randomized controlled trial of intrapartum fetal heart rate monitoring","volume":"152","author":"MacDonald","year":"1985","journal-title":"Am J Obstet Gynecol"},{"key":"B8","doi-asserted-by":"publisher","first-page":"968","DOI":"10.1111\/j.1471-0528.2010.02565.x","article-title":"How often is a low Apgar score the result of substandard care during labour?","volume":"117","author":"Berglund","year":"2010","journal-title":"BJOG"},{"key":"B9","doi-asserted-by":"publisher","first-page":"287","DOI":"10.1016\/0020-7101(90)90032-P","article-title":"Criteria for the design of fetal heart rate analysis systems","volume":"25","author":"Dawes","year":"1990","journal-title":"Int J Biomed Comput"},{"key":"B10","doi-asserted-by":"publisher","first-page":"361","DOI":"10.1067\/mob.2000.107665","article-title":"A comparison of visual analyses of intrapartum fetal heart rate tracings according to the new national institute of child health and human development guidelines with computer analyses by an automated fetal heart rate monitoring system","volume":"183","author":"Devoe","year":"2000","journal-title":"Am J Obstet Gynecol"},{"key":"B11","doi-asserted-by":"publisher","first-page":"688","DOI":"10.1111\/j.1471-0528.1995.tb11425.x","article-title":"A multicentre comparative study of 17 experts and an intelligent computer system for managing labour using the cardiotocogram","volume":"102","author":"Keith","year":"1995","journal-title":"BJOG"},{"key":"B12","doi-asserted-by":"publisher","first-page":"13","DOI":"10.1016\/j.ijgo.2015.06.020","article-title":"FIGO consensus guidelines on intrapartum fetal monitoring: cardiotocography","volume":"131","author":"Ayres-de Campos","year":"2015","journal-title":"Int J Gynecol Obstet"},{"key":"B13","doi-asserted-by":"publisher","first-page":"93","DOI":"10.1515\/jpm-2012-0067","article-title":"An overview of central fetal monitoring systems in labour","volume":"41","author":"Nunes","year":"2013","journal-title":"J Perinat Med"},{"key":"B14","doi-asserted-by":"publisher","first-page":"68","DOI":"10.1016\/j.bpobgyn.2015.02.009","article-title":"Computer analysis of foetal monitoring signals","volume":"30","author":"Nunes","year":"2016","journal-title":"Best Pract Res Clin Obstet Gynaecol"},{"key":"B15","first-page":"82","article-title":"A new, lightweight fetal telemetry system","volume":"46","author":"Boos","year":"1995","journal-title":"Hewlett Packard J"},{"key":"B16","doi-asserted-by":"publisher","first-page":"21","DOI":"10.1111\/j.1471-0528.1993.tb10631.x","article-title":"Signal processing and display\u2013cardiotocographs","volume":"100","author":"Carter","year":"1993","journal-title":"BJOG"},{"key":"B17","doi-asserted-by":"publisher","first-page":"665","DOI":"10.1007\/s11517-013-1036-7","article-title":"Comparison of real beat-to-beat signals with commercially available 4 Hz sampling on the evaluation of foetal heart rate variability","volume":"51","author":"Gon\u00e7alves","year":"2013","journal-title":"Med Biol Eng Comput"},{"key":"B18","doi-asserted-by":"publisher","first-page":"307","DOI":"10.1088\/0967-3334\/27\/3\/008","article-title":"Internal versus external intrapartum foetal heart rate monitoring: the effect on linear and nonlinear parameters","volume":"27","author":"Gon\u00e7alves","year":"2006","journal-title":"Physiol Meas"},{"key":"B19","doi-asserted-by":"publisher","first-page":"210","DOI":"10.1016\/j.bspc.2019.02.016","article-title":"Digital cardiotocography: what is the optimal sampling frequency?","volume":"51","author":"Romagnoli","year":"2019","journal-title":"Biomed Signal Proc Control"},{"key":"B20","doi-asserted-by":"publisher","first-page":"255","DOI":"10.3389\/fphys.2017.00255","article-title":"Heart rate fragmentation: a new approach to the analysis of cardiac interbeat interval dynamics","volume":"8","author":"Costa","year":"2017","journal-title":"Front Physiol"},{"key":"B21","doi-asserted-by":"publisher","first-page":"827","DOI":"10.3389\/fphys.2017.00827","article-title":"Heart rate fragmentation: a symbolic dynamical approach","volume":"8","author":"Costa","year":"2017","journal-title":"Front Physiol"},{"key":"B22","doi-asserted-by":"publisher","first-page":"861","DOI":"10.1016\/0002-9378(77)90119-3","article-title":"A simple method of fetal and neonatal heart rate beat-to-beat variability quantitation: preliminary report","volume":"127","author":"Modanlou","year":"1977","journal-title":"Am J Obstet Gynecol"},{"key":"B23","article-title":"A possible mechanism for the increase in FHR variability following hypoxemia","author":"Druzen","year":"1979","journal-title":"Presented Before the 26th Annual Meeting of the Society for Gynecologic Investigation"},{"key":"B24","doi-asserted-by":"publisher","first-page":"e215","DOI":"10.1161\/01.CIR.101.23.e215","article-title":"PhysioBank, PhysioToolkit, and PhysioNet: components of a new research resource for complex physiologic signals","volume":"101","author":"Goldberger","year":"2000","journal-title":"Circulation"},{"key":"B25","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1186\/1471-2393-14-16","article-title":"Open access intrapartum CTG database","volume":"14","author":"Chud\u00e1\u010dek","year":"2014","journal-title":"BMC Pregnancy Childbirth"},{"key":"B26","doi-asserted-by":"publisher","first-page":"61","DOI":"10.1515\/jpme.1991.19.1-2.61","article-title":"The Porto system for automated cardiotocographic signal analysis","volume":"19","author":"Bernardes","year":"1991","journal-title":"J Perinat Med"},{"key":"B27","doi-asserted-by":"publisher","first-page":"62","DOI":"10.3109\/14767058.2016.1161750","article-title":"SisPorto 4.0-computer analysis following the 2015 FIGO guidelines for intrapartum fetal monitoring","volume":"30","author":"Ayres-de Campos","year":"2017","journal-title":"J Matern Fetal Neonatal Med"},{"key":"B28","unstructured":"R CoreTeam\n          R: A Language and Environment for Statistical Computing2019"},{"key":"B29","doi-asserted-by":"publisher","first-page":"243","DOI":"10.1515\/jpme.1983.11.5.243","article-title":"Clinical significance of short-term variability computed from heart-rate waveforms","volume":"11","author":"Maulik","year":"1983","journal-title":"J Perinat Med"},{"key":"B30","doi-asserted-by":"publisher","first-page":"507","DOI":"10.12891\/ceog17322014","article-title":"Prolonged saltatory fetal heart rate pattern leading to newborn metabolic acidosis","volume":"41","author":"Nunes","year":"2014","journal-title":"Clin Exp Obstet Gynecol"}],"container-title":["Frontiers in Pediatrics"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fped.2021.662101\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,9,4]],"date-time":"2021-09-04T02:13:17Z","timestamp":1630721597000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fped.2021.662101\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,9,1]]},"references-count":30,"alternative-id":["10.3389\/fped.2021.662101"],"URL":"https:\/\/doi.org\/10.3389\/fped.2021.662101","relation":{},"ISSN":["2296-2360"],"issn-type":[{"value":"2296-2360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,9,1]]},"article-number":"662101"}}