In the second phase of the study, we want to know if the different traces acquired from the same fetus through transabdominal ECG and Doppler CTG may have different interpretations and may lead to different obstetric attitudes. In order to do that we will retrospectively analyze all the independent traces through a computer analysis (Omniview-SisPorto program). This system emits visual and sound alerts when features associated with poor fetal oxygenation are detected and has been shown to provide analysis that is in good agreement with a consensus of experts. The main outcome will be the agreement of alerts displayed by each signal acquisition technique regarding the same fetus.