Up-Down Determination of the ED90 of Metaraminol to Treat Hypotension During Cesarean Section

Inclusion Criteria: * Elective CS under spinal anesthesia * Normal singleton pregnancy beyond 36 weeks gestation * ASA physical status I/II * Age over 18 years Exclusion Criteria: * Patient refusal * Allergy to metaraminol * Preexisting or pregnancy-induced hypertension * Cardiovascular or cerebrovascular disease * Fetal abnormalities