Icon Legend

This session is not in your schedule.

This session is in your schedule. Click again to remove it.

Presentation Icons

Additional registration fee required

Faculty have requested this content not be shared outside of the session

CME Credit Offered

Abstract Award

Recording available 2/16-5/2

AIUM Credit

Foundation Awardee

Poster Icons

Abstract Award

Foundation Awardee

Poster Session 3

Category: Clinical Obstetrics

Poster Session 3

(798) Identifying Optimal Maternal Oxygen Saturation Targets Using Electronic Fetal Monitoring

Thursday, February 12, 2026

10:30 AM - 12:00 PM

Submitting Author and Presenting Author(s)

HB

Haley E. Baker, MD (she/her/hers)

Fellow
Washington University School of Medicine
Washington University School Of Medicine, Missouri, United States

Coauthor(s)

MD

Michael Dombrowski, MD

Assistant Professor
Washington University School of Medicine
St. Louis, Missouri, United States
AZ

Amanda C. Zofkie, MD

Assistant Professor
Washington University School of Medicine
St. Louis, Missouri, United States
HC

Heather Campbell, MD

Washington University School of Medicine
St Louis, Missouri, United States
Antonina I. Frolova, MD, PhD (she/her/hers)

Assistant Professor of Ob&Gyn
Washington University School of Medicine
St. Louis, Missouri, United States
Jeannie C. Kelly, MD, MS (she/her/hers)

Associate Professor
Washington University School of Medicine
Washington University School of Medicine, Missouri, United States
GM

George A. A. Macones, MD, MS, MSCE

Chair & Professor, Department of Women’s Health
Department of Women’s Health, Dell Medical School at the University of Texas at Austin
Austin, Texas, United States
Alison G. G. Cahill, MD, MSCI

Assoc. Dean, Translational Research; Prof, Women’s Health; Dir, Health Transformation Research Inst.
Department of Women’s Health, Dell Medical School at the University of Texas at Austin
Department of Women’s Health, Dell Medical School at the University of Texas at Austin, Texas, United States
NR

Nandini Raghuraman, MD, MSCI

Associate Professor
Washington University School of Medicine
St. Louis, Missouri, United States

Objective:
SMFM and ACOG recommend maintaining a maternal oxygen saturation goal of 95% to promote fetal oxygenation. However, there is a paucity of data supporting this target and some argue for permissive relative hypoxemia. We assessed the relationship between intrapartum maternal pulse oximetry and high-risk electronic fetal monitoring (EFM) features.

Study Design:
This is a secondary analysis of a prospective cohort of term, singleton pregnancies admitted for induction or spontaneous labor from 2010-2015. EFM data from the final 60 minutes (min) were abstracted by nurses blinded to outcome. Patients were included if they had at least one maternal oxygen saturation (O₂ sat) measurement at the start of the 60 min window. Those with O₂ sat < 90% were excluded due to concerns for artifact or underlying pathology. The primary outcome was a composite of high risk EFM features associated with acidemia (recurrent late or variable decelerations, >1 prolonged deceleration, minimal variability, tachycardia). Secondary outcome was umbilical artery (UA) pH. Outcomes were compared between patients with O₂ sat 90-94% versus ≥ 95% using bivariate analyses and multivariable logistic regression. Sensitivity analyses included patients with multiple O₂ sats < 95% in the last hour of labor.

Results:
Of 6,701 patients with O₂ sat and EFM data, 1,824 (27%) had O₂ sat 90–94% and 4,877 (73%) had O₂ sat ≥ 95%. Composite high risk EFM features were not significantly different between those with O₂ sat 90-94% vs ≥ 95% (aOR 0.94 (CI 0.84-1.05)). UA pH was similar between O₂ sat groups. (Table). There was no trend toward improved EFM with higher O₂ sat (Figure). Sensitivity analyses among those with multiple O₂ sat < 95% showed similar results. Results were similar when stratified by stage of labor at time of delivery.

Conclusion:
Maternal O₂ sats 90-94% appear well tolerated by the fetus as indicated by EFM features and UA pH. These findings suggest that transient, relative maternal hypoxemia in this range may be clinically acceptable in labor.