RESUMO
Intrapartum fetal hypoxia remains an important cause of neonatal permanent handicap and death, and in many cases it is related to lack of optimal fetal surveillance. In the last 40 years cardiotocography (CTG) has been routinely used for fetal monitoring yet this technique lacks reproducibility and its interpretation by healthcare professionals remains an important variable. Indeed, this technology not only does not improve clinically important outcomes, but also, on the contrary, leads to an increase in the number of caesarean sections carried out. Recent research has focused the attention on specific components of electronic fetal monitoring (EFM) tracings, such as ST-segment analysis (STAN) or fetal pulse oximetry (FPO). Fetal ST-segment analysis and pulse oximetry provide important parameters when used in addition to CTG, but their combined use obviously does not eliminate CTG interpretation limits. Although continuous electronic fetal monitoring is now ubiquitously utilized in modern practice, risks and benefits associated with its use are worth analysing. The analysis of the research and clinical practices carried out in the past several decades may provide useful insights into the current use of electronic fetal monitoring and new system associated procedures (STAN and FPO), which have influenced what has now become a routine modern obstetric practice.