Oxygen Supplementation in the Setting of Category II or III Fetal Heart Tracings

  • Practice Advisory PA
  • January 2022

This Practice Advisory was developed by the Committee on Clinical Practice Guidelines—Obstetrics with the assistance of Aaron Caughey, MD, PhD; Manisha Gandhi, MD; Anjali J. Kaimal, MD, MAS; and in collaboration with American College of Nurse Midwives Liaison Lisa Kane Low, PhD, CNM.

Intrauterine resuscitation in the setting of a Category II or III fetal heart tracing is addressed in Practice Bulletin No. 106, "Intrapartum Fetal Heart Rate Monitoring: Nomenclature, Interpretation, and General Management Principles"1. In that Practice Bulletin, it is mentioned that oxygen supplementation is commonly used for intrauterine resuscitation in cases of indeterminate or abnormal fetal heart rate patterns despite inadequate data to support its use. However, an increasing body of evidence now demonstrates no benefit of intrapartum oxygen supplementation. In a recent systematic review of 16 trials involving 2,052 women, while there was an expected slight increase in umbilical artery PaO2, there was no difference in umbilical artery pH, neonatal acidemia, admission to neonatal intensive care unit, or any other meaningful clinical outcomes 2. In a recent study involving intrapartum oxygen supplementation, the results found that oxygen supplementation did not resolve category II fetal heart rate tracings 3.

Based on this body of research, routine use of oxygen supplementation in individuals with normal oxygen saturation is not recommended for fetal intrauterine resuscitation.

Please contact [email protected] with any questions.


  1. Intrapartum fetal heart rate monitoring: nomenclature, interpretation, and general management principles. ACOG Practice Bulletin No. 106. American College of Obstetricians and Gynecologists. Obstet Gynecol 2009;114:192-202. doi: 10.1097/AOG.0b013e3181aef106
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  2. Raghuraman N, Temming LA, Doering MM, Stoll CR, Palanisamy A, Stout MJ, et al. Maternal oxygen supplementation compared with room air for intrauterine resuscitation: a systematic review and meta-analysis. JAMA Pediatr 2021;175:368-76. doi: 10.1001/jamapediatrics.2020.5351
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  3. Raghuraman N, López JD, Carter EB, Stout MJ, Macones GA, Tuuli MG, et al. The effect of intrapartum oxygen supplementation on category II fetal monitoring. Am J Obstet Gynecol 2020;223:905.e1-7. doi: 10.1016/j.ajog.2020.06.037
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