Pain relief during labor and delivery is an essential part of good obstetrical care. Labor pain and its relief have implications on the course of labor, maternal and fetal outcomes and the satisfaction with childbirth overall. Many women would like to have a choice in pain relief during labor but also would like to avoid invasive methods of pain management in labor (as epidural). Both, inhaled analgesia and parenteral opioids are common pharmacological interventions aim to relieve the pain of labor.Nitrous oxide in a 50/50 mix with oxygen is the most common concentration used for labor pain management. It is self-administered via facemask, intermittently, and has rapid onset and offset effect. Main side effects, including nausea, vomiting, dizziness and drowsiness. Pethidine is one of the most frequently used opiate agonists. It can be given intravenous or intramuscularly. Its analgesic effect starts within 10-20 minutes and lasts 2-4 hours. Reported maternal side effects include nausea, vomiting and dysphoria. Pethidine may lead to changes in fetal heart rate tracing during labor, respiratory depression, impaired sucking reflex and restlessness.