An interventional study of Maternal oxygen supplementation and Room air in Fetal Distress, Fetal Hypoxia and Labor and Delivery Complication, sponsored by Washington University School of Medicine. Recruiting at 1 site in United States. Open to female participants, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-10.
Sponsored by Washington University School of Medicine · Not applicable, Interventional, and Prevention
More than 80% of the 3 million women who labor and deliver each year in the United States undergo continuous electronic fetal monitoring (EFM) during labor in order to fetal hypoxia and prevent the transition to acidemia, expedited operative delivery, and/or neonatal morbidity. Category II EFM is the most commonly observed group of fetal heart rate features in labor. One common response to Category II EFM is maternal oxygen (O2) supplementation. The theoretic rationale for O2 administration is that it increases O2 transfer to a hypoxic fetus. There are conflicting national guidelines regarding O2 administration - the American College of Obstetricians and Gynecologists suggest O2 is ineffective, whereas the Association of Women's Health, Obstetric, and Neonatal Nurses recommend continued use given lack of definitive data on safety and efficacy. A recent national survey of nearly 600 Labor \& Delivery providers in February 2022 revealed that 49% still use O2 . Thus, there remains equipoise on the topic and high-quality data on the safety of intrapartum O2 is needed. None of the trials to date have studied the effect of intrapartum O2 on important clinical measures of neonatal or maternal morbidity. This safety data is imperative because the field of obstetrics must hold supplemental O2 to the same rigorous standards applied to any drug used in pregnancy. Without data on these definitive outcomes, it will be challenging to implement evidence-based recommendations for supplemental O2 use on Labor \& Delivery. The investigators will conduct a large, multicenter, randomized noninferiority trial of O2 supplementation versus room air in patients with Category II EFM in labor.
37 studies on the registry are indexed under Fetal Distress; 7 are open to participants now.
This study's planned enrollment of 2,252 is above the median of 116 across 25 interventional studies indexed under Fetal Distress.
Browse Fetal Distress studies →Washington University School of Medicine is the lead sponsor of 1,803 studies on the registry; 271 are open to participants now.
Of its 329 completed or terminated interventional studies of FDA-regulated products, 216 (66%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Other: Maternal oxygen supplementation
Other: Room air
Maternal oxygen supplementation 10 liters/minute via nonrebreather mask
Room air, no mask
Percentage of neonates meeting criteria for composite neonatal morbidity
One of the following diagnoses: Neonatal death, acidemia, meconium aspiration with pulmonary hypertension, hypoglycemia, hypoxic ischemic encephalopathy ,hypothermia treatment, seizure, respiratory distress
Time frame: Up to 28 days of life
Perentage of patients with operative delivery (cesarean or operative vaginal delivery)
Time frame: At delivery
Percentage of patients with operative delivery for the indication of nonreassuring fetal status
Time frame: At delivery
Percentage of neonates with neonatal death
Time frame: 28 days of life
Percentage of neonates with acidemia (pH<7.1)
On delivery cord gas
Time frame: At time of delivery
Percentage of neonates with meconium aspiration with pulmonary hypertension
Time frame: Within 72 hours of delivery
Percentage of neonates with hypoglycemia
Time frame: Within 24 hours of delivery
Percentage of neonates with hypoxic ischemic encephalopathy
Time frame: Within 72 hours of delivery
Percentage of neonates with hypothermia treatment
Time frame: Within 72 hours of delivery
Percentage of neonates with seizure
Time frame: 28 days of life
Percentage of neonates with respiratory distress
Time frame: Within 72 hours of delivery
umbilical artery base excess
Time frame: At delivery
umbilical artery partial pressure oxygen
Time frame: At delivery
umbilical artery partial pressure carbon dioxide
Time frame: At delivery
Percentage of patients with composite maternal morbidity
any diagnosis of the following: postpartum hemorrhage \[estimated blood loss \>1000 mL\]; severe perineal laceration, endometritis
Time frame: Within 2 weeks of delivery
Apgars at 5 and 10 minutes
Time frame: At 5 and 10 minutes of neonatal life
Apgar<5 at 5 and 10 mins
Time frame: At 5 and 10 minutes of neonatal life
Percentage of neonates with Neonatal Intensive care unit admission
Time frame: Within 72 hours of delivery
Plan to share: Yes — The investigators will plan to share de-identified participant data and outcomes, study protocol, and analytic code via the NICHD Data and Specimen Hub (DASH).
Supporting information: Study protocol, Statistical analysis plan, Analytic code
Time frame: Upon publication of primary analysis and planned secondary analyses.
No publications or documents are linked to this record.
Started May 2023 (actual). Primary completion is estimated for Feb 2028, 57 months after the start.
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