On the multidimensional inverse problem of spectral analysis V V Dubrovskii -Low-complexity intrauterine pressure estimation using the Teager energy operator on electrohysterographic recordings Michael J Rooijakkers, Chiara Rabotti, S Guid Oei et al. Abstract. The monitoring and analysis of antepartum fetal and maternal recordings is a research area of notable interest due to the relatively high value of preterm birth. The interest stems from the improvement of devices used for monitoring. The current paper presents the spectral analysis of antepartum heart rate recordings conducted during a study in Romania at the Cuza Voda Obstetrics and Gynecology Clinical Hospital from Iasi between 2010 and 2014. The study focuses on normal and preterm birth risk subjects in order to determine differences between these two types or recordings in terms of spectral analysis. IntroductionPreterm birth risk is an issue of interest for health care professionals given the most recent European statistics presented in the European Perinatal Health Report 2010 [1], which show rates is between 5 and 10% for all European countries, and 8% for Romania. A method used due to the advancement of technology is fetal and maternal monitoring that can be done both invasively and non-invasively. Of course, non-invasively techniques are desired due to the low risk involved for both the mother and the child. These devices are attached to the patient's abdomen and acquire data from the mother and the fetus. The data acquired can vary, but the main signals are the fetal and maternal heart rate and the maternal uterine contractions [2]. Long term monitoring of these parameters during the later stages of pregnancy, the third trimester, can be used as a screening technique in order to reduce preterm birth risk. The monitoring technique is always accompanied by the expertise of health care professionals [3]. The results presented in this paper represent the spectral analysis of antepartum recordings of fetal and maternal heart rate (FHR and MHR) during the third trimester of pregnancy. The analysis focuses on both normal and preterm birth risk recordings in order to determine the differences between the two types of recordings. The spectral analysis method is well established as a reliable method for identifying relevant information from HR recordings [4]. The method can be used for long term recordings, such as those acquired during fetal and maternal monitoring. The purpose is to show the efficiency of this type of clinical practice as a complimentary procedure to standard testing such as echography during key stages of pregnancy and close observation from health care specialists.