Maternal and fetal effects of analgesia and anesthesia in spontaneous labor

Abstract

Labor analgesia is an important aspect of obstetrics, because it significantly influences the process, quality, result and costs of medical management of labor and delivery. From this perspective, one of the most urgent and not fully resolved issues, that requires further studies, is the efficacy and safety of anesthesiological management of spontaneous vaginal delivery. The review presents detailed information on the effects of labor pain on the fetus and on pathophysiological characteristics of the mother giving spontaneous vaginal birth. The authors discuss the influence of narcotic analgesics, neuroaxial analgesia and inhalation analgesia on perinatal and obstetric outcomes, duration of labor and delivery, rates of surgical delivery, with assessment of their side effects, patient's satisfaction with the quality of analgesia, as well as fetal status at birth, neurological status and umbilical blood gases. The use of narcotic analgesics is associated with the risks of inadequate analgesia and such adverse reactions as nausea, vomiting, dizziness in the mother and respiratory suppression in the newborn. Regional analgesia with highly concentrated analgesic solution is associated with pelvic muscle relaxation that may result in the fetus malposition and an increase in duration of delivery. Inhalation of nitrogen monoxide for labor analgesia is no longer used due to its low effectiveness and frequent side effects. The analysis of few publications on the use of inhalation anesthesia with flurane derivatives shows an absence of papers with detailed description of its safety, maternal and fetal effects of an inhalational anesthetic and its influence on perinatal and obstetric outcomes. Thus, the apparent well-doing of the methods used for labor analgesia and anesthesia is rather relative, and we believe that many issues of anesthesiological management have not been unequivocally resolved from the perspective of their effects on the mother, fetus and the newborn.

Keywords

• labor pain
• fetus
• inhalation anesthesia
• narcotic analgesic
• epidural analgesia
• spontaneous delivery
• caesarian section