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- Simultaneous computerized analysis of maternal and heart rate recordings during laborPublication . Pinto, PaulaAlthough the use of cardiotocography monitoring in industrialized countries is widespread, and there is obviously an intimate relationship between the mother and the fetus during pregnancy, few studies have been published about the relationship between maternal heart rate (MHR) and fetal heart rate (FHR) during labor. The main objective of this thesis was to explore whether combined analysis of MHR and FHR could improve maternal and fetal monitoring during labor. To overcome the limitations and subjectivity of common visual analysis, we developed and validated a new computerized program for simultaneous MHR and FHR analysis based on a previously developed program for FHR analysis alone, supported in the International Federation of Gynaecology and Obstetrics (FIGO) guidelines for fetal monitoring (Chapter 2). Good to excellent computer-observer agreement and reliability were obtained, and the detection of MHR changes associated with labor progression were studied. In fact, the morphologic similarity and sometimes coincidence between MHR and FHR, and the well-known possibility of misinterpreting the MHR as FHR, lead us to the assessment of an algorithm to detect and delete MHR-FHR ambiguities (Chapter 3). Improvements in FHR tracing analysis were obtained, with a significant increase of FHR signal loss of 1% and 6%, in cases with minor and major ambiguities, respectively, as well as a significant decrease in FHR decelerations. Then, to accomplish our main objective, we explored the application of combined conventional (Chapter 4) and non-conventional (Chapter 5) computerized analysis of MHR and FHR recordings in the assessment of labor progression, fetal acidemia, and maternal-fetal attachment. With conventional analyses, the progression of labor was associated with a significant increase in MHR accelerations and FHR decelerations both in non-acidemic and acidemic fetuses (p<0.01). In acidemic fetuses, there was an increase in MHR-FHR correlations and differences in accelerations and decelerations with modest area under the ROC curve (auROC) results. With non-conventional analyses, the progression of labor was also associated with a significant increase in most MHR and FHR linear indices, whereas entropy indices decreased. The inclusion of MHR on bivariate analysis achieved sensitivity and specificity values of nearly 100% and 89.1%, respectively. These two studies represent the first combined MHR and FHR analysis in relation to labor progress and prediction of newborn acidemia. Finally, to study an easier and alternative method of acquiring MHR signals, we explored the use of pulse oximetry using photoplethysmography (PPG) as an alternative method to electrocardiography (ECG) (Chapter 6). The study has evidenced PPG as an alternative for MHR acquiring signal and monitoring during labor, when appropriate MHR variability indices and reference ranges are used. In conclusion, our exploratory studies suggest that combined MHR-FHR analysis may improve maternal-fetal monitoring during labor in several ways. More extensive studies are warranted.