Supplemental Oxygen Study

Objective:

To compare umbilical cord gases in subjects receiving oxygen at 10L/min via simple facemask to subjects receiving room air in those presenting for scheduled cesarean sections. The investigators hypothesize that umbilical artery pH levels will not be significantly lowered in the oxygenated group.

Primary outcome: umbilical artery pH levels in the oxygenated versus room air group

Secondary outcomes: Apgars, respiratory distress syndrome, necrotizing enterocolitis, interventricular hemorrhage, intubation, number of NICU days and neonatal mortality.

Methods:

Only term elective c-sections will be approached for study consent. Once enrolled subjects will be randomized either receive 10L/min via simple facemask or to room air. Once regional anesthesia is completed, then the facemask with oxygen will be placed. The time from oxygen administration to uterine incision will be at least 10 min. At the time of delivery umbilical cord gases will be collected by and will be processed within one hour of delivery.

Inclusion criteria

• 18 years or older
• Scheduled cesarean section
• Singleton
• Term gestation; at 37 0/7 weeks gestation or greater

Exclusion criteria

• Maternal lung disease including asthma
• Evidence of hypoxemia prior to enrollment
• Intrauterine growth restriction
• Chronic hypertension
• Preeclampsia
• Fetal anomalies
• Breech position
• Multiple Gestation

Statistical analysis:

Subjects will be randomized via block randomization. The estimated umbilical arterial pH in the scheduled cesarean section room air group is 7.31. To identify a 0.05 or greater difference between the control and treatment group, a power of 0.8, alpha of 0.05 the investigators would need 64 subjects total. To account for drop out the investigators intend to enroll a total of 70 subjects.

Inclusion criteria

• 18 years or older
• Scheduled cesarean section
• Singleton
• Term gestation

Exclusion criteria

• Maternal lung disease including asthma
• Evidence of hypoxemia prior to enrollment
• Intrauterine growth restriction
• Chronic hypertension
• Preeclampsia
• Fetal anomalies
• Breech position
• Multiple gestation