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Investigations in Gynecology Research & Womens Health

Importance of Hypoxia Index in FHR Monitoring

  • Open or Close Kazuo Maeda*

    Honorary professor, Department of Obstetrics and Gynecology, Tottori University Medical School, Japan

    *Corresponding author: Kazuo Maeda, Honorary professor, Department of Obstetrics and Gynecology, Tottori University Medical School, Yonago, Japan, Email:

Submission: October 16, 2017; Published: December 20, 2017

DOI: 10.31031/IGRWH.2017.01.000517

ISSN: 2577-2015
Volume1 Issue4


Aim: Numeric objective evaluation of FHR deceleration.

Methods and results: Hypoxia index (HI) is the sum of deceleration duration (min) divided by the lowest FHR (bpm), and x 100. As the HI was 25 in a case of FHR decelerations followed by the loss of variability and cerebral palsy (CP), and the HI was 26 in a case of repeated late decelerations for 50 min with the loss of variability, Apgar 3, and brain damage, the HI below 25 at delivery would be safe, showing neither brain damage nor CP, namely, the HI of 3 connected lare decelerations was 6 and Apgar was 9, without CP. Also HI values of repeated abnormalities were 20-24 preserving the FHR variability, without brain damage.

Conclusion: The late, early, mild and severe decelerations and sudden acute FHR bradycardia would not be followed neither by brain damage nor CP, when the variability is preserved , and the HI is lower than 25. Thus, it is recommended to decide early caesarean delivery, when the HI is 20 or less, considering the time to prepare the surgery, while no normal neonate may be guaranteed by the caesarean delivery performed after the higher hypoxia index of 25 or more with the loss of FHR variability. The other sign of ominous outcome will be pathologic sinusoidal FHR, which mean severe fetal anemia

Keywords: Fetus; Hypoxia index; FHR deceleration; Late deceleration; Variable deceleration; Acceleration; Variability; Cerebral palsy; Apgar score; Long term FHR variability

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