Effect of Ephedrine vs. Norepinephrine on Prevention of Fetal Acidosis During Cesarean Section Under Spinal Anesthesia

This is a prospective, randomized, double-blind, controlled clinical trial designed to compare the effects of ephedrine and norepinephrine on fetal acidosis during cesarean section performed under spinal anesthesia. Maternal hypotension is a frequent complication associated with spinal anesthesia, and the management of this condition is critical for maintaining adequate uteroplacental perfusion. While both ephedrine and norepinephrine are commonly used vasopressors, there is ongoing debate regarding their relative safety and efficacy, particularly in terms of fetal outcomes.

The primary aim of this study is to evaluate the incidence of fetal acidosis, defined as an umbilical artery pH < 7.20, in patients receiving either ephedrine or norepinephrine. Secondary outcomes include maternal blood pressure control, heart rate, incidence of maternal and fetal tachycardia, Apgar scores at 1 and 5 minutes, and the need for additional vasopressor support. A total of 100 pregnant women undergoing elective cesarean section will be enrolled, with 50 participants in each treatment group. All participants will receive standardized spinal anesthesia, and vasopressors will be titrated according to protocol.

The study is designed to inform clinical decision-making regarding optimal vasopressor selection in obstetric anesthesia, with a focus on balancing maternal hemodynamic stability and fetal well-being.

Inclusion criteria

• Pregnant women aged between 18 and 45 years
• Singleton pregnancy at ≥ 37 weeks of gestation
• Scheduled for elective cesarean section under spinal anesthesia
• ASA (American Society of Anesthesiologists) physical status classification I or II
• Ability to understand and sign the informed consent form

Exclusion criteria

• History of allergy or hypersensitivity to ephedrine or norepinephrine
• Multiple gestation pregnancies
• Diagnosis of pre-eclampsia, eclampsia, or other hypertensive disorders of pregnancy
• Known cardiovascular disease or arrhythmia
• Placental abnormalities (e.g., placenta previa, placental abruption)
• Fetal structural or chromosomal anomalies
• Morbid obesity (BMI > 40 kg/m²)
• Refusal to participate or inability to provide informed consent