Background: Maternal hypotension resulting from spinal anesthesia, along with the interval between anesthetic administration and delivery, are considered potential modifiable risk factors contributing to the development of transient tachypnea of the newborn (TTN) and fetal acidosis.

Objective: To investigate the precise impact of maternal hypotension triggered by spinal anesthesia and the duration of anesthesia-to-delivery intervals on neonatal outcomes, primarily the incidence of TTN and fetal acid-base imbalance among women undergoing planned cesarean section (CS) deliveries.

Methods: A pre-planned prospective cohort study was conducted over a one-year period at a tertiary care center, enrolling all women with non-anomalous singleton pregnancies between 37 and 41 weeks of gestation who delivered via elective CS under spinal anesthesia. The main outcome variables were the incidence of neonatal respiratory morbidity, specifically TTN, and fetal acidosis, evaluated in relation to maternal intraoperative hypotension and the interval from induction of anesthesia to delivery. Intraoperative maternal blood pressure profiles were systematically compared between neonates with TTN and those without.

Results: A total of 115 maternal-infant dyads were included in the final analytical cohort. Neonates who developed TTN were delivered by mothers who experienced more profound intraoperative hypotension, evidenced by significantly lower minimum systolic blood pressure (SBP) (P = 0.006), diastolic blood pressure (DBP) (P = 0.01), and mean arterial pressure (MAP) (P = 0.003). Notably, maternal baseline MAP demonstrated a considerable inverse correlation with umbilical cord pH (r = -0.473, P < 0.001), whereas minimum MAP correlated positively (r = 0.324, P < 0.001). Multivariate analyses identified both the severity and duration of maternal hypotension as significant independent predictors of TTN and fetal acidosis.

Conclusion: Implementing preventive measures against maternal spinal hypotension is a prudent strategy to minimize the likelihood of neonatal acidosis and reduce the risk of TTN in scheduled cesarean deliveries.