Objective: to evaluate the risk of obstetric and perinatal outcomes in teenage pregnancy in comparison with adult pregnancy. Methods: retrospective cohort study of 67.693 pregnant women attended in a public hospital in Lima between 2000 and 2010. Obstetric and perinatal outcomes were evaluated. The adolescent group was divided in late adolescents (15-20 years), and early adolescents (<15 years) and was compared among the adult group (20-35 years). Adjusted odds ratios were calculated by education, civil status, prenatal care, previous pregnancies, parity, and pre-gesta-tional BMI. Results: higher risk of cesarean (OR=1,28; CI95%=1,07-1,53) and puerperal infection (OR=1,72; CI95%=1,17-2,53) was found in teenager under 15 years old; as well as higher risk of episiotomy (OR=1,34; CI95%=1,29-1,40) in late teenagers. In addition, this study identified a lower risk of teenage pregnancy for preeclampsia (OR=0,90; CI95%=0,85-0,97), 2nd half-pregnancy bleeding (OR=0,80; CI95%=0,71-0,92), premature rupture of membranes(OR=0,83; CI95%=0,79-0,87), preterm labor (OR=0,87; CI95%=0,80-0,94) and vaginal tearing (OR=0,86; CI95%=0,79-0,93). Conclusion: pregnancy behaves as a risk factor for some obstetric outcomes in the adolescent group, especially in the youngest ones. In addition to maternal age, there are other factors that constitute the need to form multidisciplinary teams to reduce obstetric outcomes in this population. / diego.maticorena@gmail.com / Objetivos: analizar el riesgo de complicaciones obstétricas y perinatales en adolescentes embarazadas en un hospital de Lima, Perú. Métodos: estudio de cohorte retrospectiva de 67.693 gestantes atendidas en el período 2000-2010. Se evaluó complicaciones obstétricas y perinatales. Las adolescentes se clasificaron en tardías (15-19 años) y tempranas (< 15 años) y se compararon con las adultas (20-35 años). Se calculó OR ajustados por educación, estado civil, control prenatal, gestaciones previas, paridad e IMC pregestacional. Resultados: se encontró mayor riesgo de cesárea (OR=1,28; IC95%=1,07-1,53) e infección puerperal (OR=1,72; IC95%=1,17-2,53) en las adolescentes menores de 15 años, así como mayor riesgo (OR=1,34; IC95%=1,29-1,40)de episiotomía en las adolescentes tardías. Asimismo, se identificó un menor riesgo del embarazo adolescente para preeclampsia (OR=0,90; IC95%=0,85-0,97), hemorragia de la 2da mitad del embarazo (OR=0,80; IC95%=0,71-0,92), ruptura prematura de membranas (OR=0,83; IC95%=0,79-0,87), amenaza de parto pretérmino (OR=0,87; IC95%=0,80-0,94) y desgarro vaginal (OR= 0,86; IC95%=0,79-0,93). Conclusión: el embarazo se comporta como factor de riesgo para ciertas complicaciones obstétricas en la población adolescente, especialmente en las adolescentes tempranas. Existen además otros factores, que sumados a la edad materna, constituyen la necesidad de formar equipos multidis-ciplinarios para reducir complicaciones obstétricas en esta población. / Revisión por pares

The non-invasive fetal ECG (NIFECG), derived from abdominal surface electrodes, offers novel diagnostic possibilities for prenatal medicine. Despite its straightforward applicability, NIFECG signals are usually corrupted by many interfering sources. Most significantly, by the maternal ECG (MECG), whose amplitude usually exceeds that of the fetal ECG (FECG) by multiple times. The presence of additional noise sources (e.g. muscular/uterine noise, electrode motion, etc.) further affects the signal-to-noise ratio (SNR) of the FECG. These interfering sources, which typically show a strong non-stationary behavior, render the FECG extraction and fetal QRS (FQRS) detection demanding signal processing tasks. In this thesis, several of the challenges regarding NIFECG signal analysis were addressed. In order to improve NIFECG extraction, the dynamic model of a Kalman filter approach was extended, thus, providing a more adequate representation of the mixture of FECG, MECG, and noise. In addition, aiming at the FECG signal quality assessment, novel metrics were proposed and evaluated. Further, these quality metrics were applied in improving FQRS detection and fetal heart rate estimation based on an innovative evolutionary algorithm and Kalman filtering signal fusion, respectively. The elaborated methods were characterized in depth using both simulated and clinical data, produced throughout this thesis. To stress-test extraction algorithms under ideal circumstances, a comprehensive benchmark protocol was created and contributed to an extensively improved NIFECG simulation toolbox. The developed toolbox and a large simulated dataset were released under an open-source license, allowing researchers to compare results in a reproducible manner. Furthermore, to validate the developed approaches under more realistic and challenging situations, a clinical trial was performed in collaboration with the University Hospital of Leipzig. Aside from serving as a test set for the developed algorithms, the clinical trial enabled an exploratory research. This enables a better understanding about the pathophysiological variables and measurement setup configurations that lead to changes in the abdominal signal's SNR. With such broad scope, this dissertation addresses many of the current aspects of NIFECG analysis and provides future suggestions to establish NIFECG in clinical settings.:Abstract Acknowledgment Contents List of Figures List of Tables List of Abbreviations List of Symbols (1)Introduction 1.1)Background and Motivation 1.2)Aim of this Work 1.3)Dissertation Outline 1.4)Collaborators and Conflicts of Interest (2)Clinical Background 2.1)Physiology 2.1.1)Changes in the maternal circulatory system 2.1.2)Intrauterine structures and feto-maternal connection 2.1.3)Fetal growth and presentation 2.1.4)Fetal circulatory system 2.1.5)Fetal autonomic nervous system 2.1.6)Fetal heart activity and underlying factors 2.2)Pathology 2.2.1)Premature rupture of membrane 2.2.2)Intrauterine growth restriction 2.2.3)Fetal anemia 2.3)Interpretation of Fetal Heart Activity 2.3.1)Summary of clinical studies on FHR/FHRV 2.3.2)Summary of studies on heart conduction 2.4)Chapter Summary (3)Technical State of the Art 3.1)Prenatal Diagnostic and Measuring Technique 3.1.1)Fetal heart monitoring 3.1.2)Related metrics 3.2)Non-Invasive Fetal ECG Acquisition 3.2.1)Overview 3.2.2)Commercial equipment 3.2.3)Electrode configurations 3.2.4)Available NIFECG databases 3.2.5)Validity and usability of the non-invasive fetal ECG 3.3)Non-Invasive Fetal ECG Extraction Methods 3.3.1)Overview on the non-invasive fetal ECG extraction methods 3.3.2)Kalman filtering basics 3.3.3)Nonlinear Kalman filtering 3.3.4)Extended Kalman filter for FECG estimation 3.4)Fetal QRS Detection 3.4.1)Merging multichannel fetal QRS detections 3.4.2)Detection performance 3.5)Fetal Heart Rate Estimation 3.5.1)Preprocessing the fetal heart rate 3.5.2)Fetal heart rate statistics 3.6)Fetal ECG Morphological Analysis 3.7)Problem Description 3.8)Chapter Summary (4)Novel Approaches for Fetal ECG Analysis 4.1)Preliminary Considerations 4.2)Fetal ECG Extraction by means of Kalman Filtering 4.2.1)Optimized Gaussian approximation 4.2.2)Time-varying covariance matrices 4.2.3)Extended Kalman filter with unknown inputs 4.2.4)Filter calibration 4.3)Accurate Fetal QRS and Heart Rate Detection 4.3.1)Multichannel evolutionary QRS correction 4.3.2)Multichannel fetal heart rate estimation using Kalman filters 4.4)Chapter Summary (5)Data Material 5.1)Simulated Data 5.1.1)The FECG Synthetic Generator (FECGSYN) 5.1.2)The FECG Synthetic Database (FECGSYNDB) 5.2)Clinical Data 5.2.1)Clinical NIFECG recording 5.2.2)Scope and limitations of this study 5.2.3)Data annotation: signal quality and fetal amplitude 5.2.4)Data annotation: fetal QRS annotation 5.3)Chapter Summary (6)Results for Data Analysis 6.1)Simulated Data 6.1.1)Fetal QRS detection 6.1.2)Morphological analysis 6.2)Own Clinical Data 6.2.1)FQRS correction using the evolutionary algorithm 6.2.2)FHR correction by means of Kalman filtering (7)Discussion and Prospective 7.1)Data Availability 7.1.1)New measurement protocol 7.2)Signal Quality 7.3)Extraction Methods 7.4)FQRS and FHR Correction Algorithms (8)Conclusion References (A)Appendix A - Signal Quality Annotation (B)Appendix B - Fetal QRS Annotation (C)Appendix C - Data Recording GUI

Bei ca. 10 bis 20 % aller Totgeburten wird autoptisch eine Lungenhypoplasie diagnostiziert. Nierenfehlbildungen, vorzeitiger Blasensprung, Hydrops fetalis und Skelettfehlbildungen sind häufige Ursachen eines Minderwuchses der Lunge, der immer mit einer schlechten Prognose einhergeht. Bis heute gibt es jedoch kein zuverlässiges Verfahren zur pränatalen Diagnose einer Lungenhypoplasie, die das geburtshilfliche Management erheblich erleichtern könnte. Bei Totgeburten wird eine Lungenhypoplasie pathologisch-anatomisch durch einen verminderten Lungen / Körpergewichts-Index (L/KG- Index) und einen verringerten Radial Alveolar Count (RAC) belegt. Ziel dieser Studie war es, ein sonographisches Verfahren zu validieren, mit dem man eine fetale Lungenhypoplasie schon während der Schwangerschaft diagnostizieren könnte. Die Untersuchung basierte auf gestationsaltersabhängigen Referenzwerten für verschiedene Biometrieparameter, die das fetale Lungenwachstum gut erfassen. Die aufgestellten Normkurven wurden hinsichtlich ihres prädiktiven Werts zur Vorhersage einer Lungenhypoplasie geprüft. Dazu wurden Messungen bei 39 Feten mit einem hohem Risiko zur Entwicklung einer Lungenhypoplasie zwischen der 17. und 30. SSW vorgenommen. Zur Auswertung gelangten nur die 29 Fälle, bei denen der Verdacht einer Lungenhypoplasie pathologisch-anatomisch belegt oder widerlegt wurde. Die Patienten wurden vier verschiedenen Krankheitsbildern zugeordnet: Vorzeitiger Blasensprung, Hydrothorax, Nierenfehlbildungen und Skelettfehlbildungen. Es wurden jeweils der anterior-posteriore und der seitliche Durchmessers in Höhe des Zwerchfells, des Vierkammerblicks und der Clavicula sowie die Lungenlänge gemessen. Untersuchungen in der Vierkammerblickebene hatten mit einer Sensitivität von 61 % und einer Spezifität von 75 % die höchsten prädiktiven Werte zur Vorhersage einer fetalen Lungenhypoplasie. Die Untersuchung in der VKB-Ebene hat den Vorteil, daß die Einstellung dieser Ebene bei Routineultraschalluntersuchungen während der Schwangerschaft durchgeführt wird und so in der Praxis am ehesten zur Anwendung kommt. Im Vergleich zur Literatur ist unser Verfahren auch in der Vierkammerblickebene zur pränatalen Diagnose einer Lungenhypoplasie relativ unzuverlässig. Messungen in der Clavicula- und der Zwerchfellebene und Messungen der Lungenlänge waren in dieser Untersuchung zur pränatalen Diagnose einer Lungenhypoplasie ungeeignet. Mit Sensitivitäten zwischen 13 % und 47 % stellten sie keine Hilfestellung zur Vorhersage eines Minderwuchses der fetalen Lunge dar. Die Aufschlüsselung der Feten in einzelne Krankheitsbilder erbrachte weitere Informationen. Dabei wurden nur die Messungen in der VKB-Ebene ausgewertet. Bei den Feten mit vorzeitigem Blasensprung, Hydrothorax und Skelettfehlbildungen lagen die Sensitivitäten zwischen 60 % und 100 % und waren mit den Ergebnissen aus der Literatur vergleichbar. Bei den Feten mit Nierenfehlbil-dungen waren die Ergebnisse mit Sensitivitäten von 27 % enttäuschend. Bei der Auswertung wurde deutlich, daß es von großer Bedeutung ist, sowohl den anterior-posterioren als auch den seitlichen Durchmesser zu messen, da nur so zuverlässig die Ausdehnung der Lunge zu erfassen ist. Insgesamt kann das biometrische Verfahren als einfache, gut reproduzierbare, nicht invasive und schnell durchzuführende Möglichkeit zur Untersuchung der fetalen Lunge bezeichnet werden. Es kann wichtige Hinweise geben, eine Lungenhypoplasie schon pränatal zu diagnostizieren. Eine sichere Einschätzung ist jedoch nicht möglich. Neben der Lungenbiometrie könnten evtl. auch Messungen der fetalen Atembewegungen, Messungen der Fruchtwassermenge und dopplersonographische Darstellung der Lungengefäße zur Diagnose beitragen. Letztendlich bleibt eine Lungenhypoplasie eine pathologisch-anatomische Diagnose, die nur durch Autopsie gesichert werden kann. Inwiefern hier neue Aspekte in die Diagnosestellung einbezogen werden können, bleibt zukünftigen Untersuchungen vorbehalten. / Evaluation of sonographic lung biometry as a method to diagnose lung hypoplasia prenatallyIn 10 to 20 % of all stillbirths lung hypoplasia can be diagnosed by autopsy. Causes for the underdevelopment of the lung, which indicates poor prognosis, are urinary tractanomalies, preterm rupture of membranes, hydrops fetalis and skeletal dysplasia. Up to now there is no reliable method to diagnose lung hypoplasia prenatally. In stillbirths lung hypoplasia is proven by autopsy by a decreased lung/body weight index and a low radial alveolar count (RAC). Aim of this study was to evaluate a sonographic method to diagnose lung hypoplasia during pregnancy. The examination was based on normograms for different biometrical parameters, which describe the fetal lung growth between the 15th and the 30th week gestation. The predictive value of the reference curves was determined. 39 fetuses at high risk for developing lung hypoplasia were examined sonographically between the 17th and 30th week gestation. Only the measurements of 29 fetuses, whose diagnosis was proven or disproven by autopsy, were evaluated. The patients were splitted into four groups: preterm rupture of membranes, hydrothorax, urinary tract anomalies and skeletal dysplasia. In each fetus seven different parameters were measured: the anterior-posterior and the transverse diameter at the level of the diaphragm, the four chamber view and the clavicula and additionally the lung length. The best results were found at the level of the four chamber view (sensitivity 61 % and specifity 75 %). An advantage of measurements at the level of the four chamber view is that this examination is performed in normal routine Ultrasound tests during pregnancy. So measurements in this plane could become most important in clinical life. In comparison to other published studies even at the level of the four chamber view our method was not reliable to predict fetal lung hypoplasia. Measurements at the level of the clavicula and of the diaphragm and measurements of the lung length were not useful to diagnose lung hypoplasia before birth. Sensitivities between 13 and 47 % were found. Splitting the fetuses into different etiological groups gave additional information. Only the measurements at the level of the four chamber view were evaluated. In the groups preterm rupture of membranes, hydrothorax and skeletal dysplasia sensitivities between 60 and 100 % were found. These results can be compared with published results. In the group urinary tract anomalies the result was disappointing (sensitivity 27 %). During the evaluation it could be seen easily that it was very important to measure the anterior-posterior as well as the transverse diameter. Only this technique gives the possibility to measure the whole extension of the lung. Summarizing: The biometrical method is a simple, easily reproducable, not invasive and quick possibility to examine the fetal lung. It can help to predict fetal lung hypoplasia. However a reliable diagnosis could not be made. In addition to lung biometry measurements of the the fetal breathing excursions, measurements of the amount of amniotic fluid and examination of the pulmonal circulation may be useful for a prenatal diagnosis. Up to now lung hypoplasia only can be proved by autopsy. It has to be examined in future studies, if any new aspects can help to find a prenatal diagnosis.