Maternal Oxygen Supplementation for Intrauterine Resuscitation (MOXY)

Maternal Oxygen Supplementation for Intrauterine Resuscitation: a Multicenter Randomized Trial

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.

Study Overview

• Status: Recruiting
• Conditions: Fetal Hypoxia; Fetal Distress; Labor and Delivery Complication
• Intervention / Treatment: Other: Maternal oxygen supplementation; Other: Room air

• Study Type: Interventional
• Enrollment (Estimated): 2124
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Nandini Raghuraman, MD MSCI; Phone Number: 3142732939; Email: nraghuraman@wustl.edu

Study Locations

• United States
  • Missouri
    • St Louis, Missouri, United States, 63110
      • Recruiting
      • Barnes Jewish Hospital
      • Contact: Nandini Raghuraman, MD MS

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Singleton gestation
• Gestational age>=37 weeks
• Spontaneous labor or induction of labor
• English or spanish speaking
• Planned continuous fetal monitoring

Exclusion Criteria:

• Preterm gestation
• Major fetal anomaly
• Multiple gestation
• Category III fetal monitoring at time of admission
• Maternal hypoxia <95%
• Planned or scheduled cesarean delivery Excluded from randomization if receiving nitrous oxide for analgesia at time of randomization.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Oxygen	Other: Maternal oxygen supplementation; Maternal oxygen supplementation 10 liters/minute via nonrebreather mask
Active Comparator: Room air	Other: Room air; Room air, no mask

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	Up to 28 days of life

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Perentage of patients with operative delivery (cesarean or operative vaginal delivery)		At delivery
Percentage of patients with operative delivery for the indication of nonreassuring fetal status		At delivery
Percentage of neonates with neonatal death		28 days of life
Percentage of neonates with seizure		28 days of life
umbilical artery base excess		At delivery
umbilical artery partial pressure oxygen		At delivery
umbilical artery partial pressure carbon dioxide		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	Within 2 weeks of delivery
Apgars at 5 and 10 minutes		At 5 and 10 minutes of neonatal life
Apgar<5 at 5 and 10 mins		At 5 and 10 minutes of neonatal life
Percentage of neonates with acidemia (pH<7.1)	On delivery cord gas	At time of delivery
Percentage of neonates with meconium aspiration with pulmonary hypertension		Within 72 hours of delivery
Percentage of neonates with hypoglycemia		Within 24 hours of delivery
Percentage of neonates with hypoxic ischemic encephalopathy		Within 72 hours of delivery
Percentage of neonates with hypothermia treatment		Within 72 hours of delivery
Percentage of neonates with respiratory distress		Within 72 hours of delivery
Percentage of neonates with Neonatal Intensive care unit admission		Within 72 hours of delivery

Collaborators and Investigators

• Sponsor: Washington University School of Medicine
• Collaborators: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD); Brown University; University of Michigan; Women and Infants Hospital of Rhode Island; University of Texas at Austin; Dell Children's Medical Center of Central Texas

Study record dates

Study Major Dates

• Study Start (Actual): May 22, 2023
• Primary Completion (Estimated): February 28, 2028
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: December 14, 2022
• First Submitted That Met QC Criteria: December 27, 2022
• First Posted (Actual): January 12, 2023

Study Record Updates

• Last Update Posted (Actual): February 27, 2026
• Last Update Submitted That Met QC Criteria: February 25, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Pregnancy Complications; Fetal Diseases; Signs and Symptoms, Respiratory; Hypoxia; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Fetal Distress; Fetal Hypoxia
• Other Study ID Numbers: 202209042; R01HD108614 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: 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).
• IPD Sharing Time Frame: Upon publication of primary analysis and planned secondary analyses.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No