{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,14]],"date-time":"2025-10-14T00:50:48Z","timestamp":1760403048641,"version":"build-2065373602"},"reference-count":54,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2020,1,16]],"date-time":"2020-01-16T00:00:00Z","timestamp":1579132800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Prediction of labor is of extreme importance in obstetric care to allow for preventive measures, assuring that both baby and mother have the best possible care. In this work, the authors studied how important nonlinear parameters (entropy and compression) can be as labor predictors. Linear features retrieved from the SisPorto system for cardiotocogram analysis and nonlinear measures were used to predict labor in a dataset of 1072 antepartum tracings, at between 30 and 35 weeks of gestation. Two groups were defined: Group A\u2014fetuses whose traces date was less than one or two weeks before labor, and Group B\u2014fetuses whose traces date was at least one or two weeks before labor. Results suggest that, compared with linear features such as decelerations and variability indices, compression improves labor prediction both within one (C-Statistics of 0.728) and two weeks (C-Statistics of 0.704). Moreover, the correlation between compression and long-term variability was significantly different in groups A and B, denoting that compression and heart rate variability look at different information associated with whether the fetus is closer to or further from labor onset. Nonlinear measures, compression in particular, may be useful in improving labor prediction as a complement to other fetal heart rate features.<\/jats:p>","DOI":"10.3390\/e22010104","type":"journal-article","created":{"date-parts":[[2020,1,17]],"date-time":"2020-01-17T04:14:41Z","timestamp":1579234481000},"page":"104","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Complexity of Cardiotocographic Signals as A Predictor of Labor"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1147-5728","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Monteiro-Santos","sequence":"first","affiliation":[{"name":"Department of Community Medicine, Information and Health Decision Sciences\u2014MEDCIDS, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal"},{"name":"Center for Health Technology and Services Research\u2014CINTESIS, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal"}]},{"given":"Teresa","family":"Henriques","sequence":"additional","affiliation":[{"name":"Department of Community Medicine, Information and Health Decision Sciences\u2014MEDCIDS, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal"},{"name":"Center for Health Technology and Services Research\u2014CINTESIS, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6709-3916","authenticated-orcid":false,"given":"In\u00eas","family":"Nunes","sequence":"additional","affiliation":[{"name":"Center for Health Technology and Services Research\u2014CINTESIS, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal"},{"name":"Department of Obstetrics and Gynecology, Centro Materno-Infantil do Norte-Centro Hospitalar do Porto, 4200-450 Porto, Portugal"},{"name":"Instituto de Ci\u00eancias Biom\u00e9dicas Abel Salazar, University of Porto, 4200-450 Porto, Portugal"}]},{"given":"C\u00e9lia","family":"Amorim-Costa","sequence":"additional","affiliation":[{"name":"Center for Health Technology and Services Research\u2014CINTESIS, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal"},{"name":"Department of Obstetrics and Gynecology, Centro Materno-Infantil do Norte-Centro Hospitalar do Porto, 4200-450 Porto, Portugal"},{"name":"Department of Gynecology-Obstetrics and Pediatrics, Faculty of Medicine of University of Porto, 4200-450 Porto, Portugal"}]},{"given":"Jo\u00e3o","family":"Bernardes","sequence":"additional","affiliation":[{"name":"Center for Health Technology and Services Research\u2014CINTESIS, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal"},{"name":"Department of Gynecology-Obstetrics and Pediatrics, Faculty of Medicine of University of Porto, 4200-450 Porto, Portugal"},{"name":"Centro Hospitalar Universit\u00e1rio de S. Jo\u00e3o, Alameda Hern\u00e2ni Monteiro, 4200-101 Porto, Portugal"}]},{"given":"Cristina","family":"Costa-Santos","sequence":"additional","affiliation":[{"name":"Department of Community Medicine, Information and Health Decision Sciences\u2014MEDCIDS, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal"},{"name":"Center for Health Technology and Services Research\u2014CINTESIS, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2020,1,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1016\/S0140-6736(14)60496-7","article-title":"Every newborn: Progress, priorities, and potential beyond survival","volume":"384","author":"Lawn","year":"2014","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"430","DOI":"10.1016\/S0140-6736(14)61698-6","article-title":"Global, regional, and national causes of child mortality in 2000\u201313, with projections to inform post-2015 priorities: An updated systematic analysis","volume":"385","author":"Liu","year":"2015","journal-title":"Lancet"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"S2","DOI":"10.1186\/1742-4755-10-S1-S2","article-title":"Born too soon: The global epidemiology of 15 million preterm births","volume":"10","author":"Blencowe","year":"2013","journal-title":"Reprod. 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