In term patients with obesity undergoing cesarean delivery under spinal anesthesia, arm and ankle blood pressure measurements showed poor agreement, with arm values consistently lower and wide limits of agreement, indicating they are not interchangeable. In this prospective study of 97 patients, ankle-derived hypotension, particularly a ≥30% decrease in mean arterial pressure from baseline, was a strong independent predictor of NICU admission, whereas arm-based measurements were not associated with neonatal outcomes. These findings suggest that ankle blood pressure monitoring may better detect clinically significant hemodynamic changes such as occult aortocaval compression and provide superior risk stratification for neonatal morbidity in this high-risk population.