Magnesium for Neonatal Neuroprotection and Mothers

Inclusion Criteria: * Delivering by cesarean section at less than 34 weeks gestational age (maximum 33 weeks and 6 days). * ≥19 yr * Singleton or multiple pregnancy o There is potentially greater intra-abdominal pressure associated with multiple pregnancies, which may affect anesthetic block height by increasing blood volume in epidural blood vessels. It may also increase the risk of basal atelectasis and will affect respiratory mechanics to a greater extent. We plan to undertake sub-group analysis to test this effect. * Primiparous or multiparous * English-speaking * Undergoing cesarean section with neuraxial anesthesia (intrathecal, epidural or combined spinal epidural \[CSE\]). * Parturients response may not be identical to the different neuraxial techniques, e.g. the degree of respiratory motor blockade exhibited or onset of opioid effect. Therefore we plan to undertake sub-group analysis to test this effect. Exclusion Criteria: * Illegal, non-prescription drug use within the last year * Psychiatric disorder treated with medication within the last year