Umbilical cord blood acid-base analysis at delivery
- Susan M Ramin, MD
Susan M Ramin, MD
- Section Editor — Obstetrics
- Professor of Obstetrics and Gynecology
- Baylor College of Medicine
Fetal acid-base balance can be assessed in a number of ways:
●Antepartum, by percutaneous umbilical cord blood sampling (see "Fetal blood sampling")
●Intrapartum, by fetal scalp blood sampling (see "Intrapartum fetal heart rate assessment", section on 'Fetal scalp blood sampling')
●Immediately after birth, by umbilical cord blood sampling
Information from umbilical cord blood sampling immediately after birth can be useful from medical and medicolegal perspectives since it provides insight into intrapartum fetal physiology. This topic will review basic concepts of fetal acid-base physiology and discuss the clinical use of umbilical cord acid-base analysis at delivery.
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- FETAL ACID-BASE PHYSIOLOGY
- Acids and buffers
- Differences from postnatal acid-base physiology
- INDICATIONS FOR FETAL ACID-BASE ANALYSIS
- TEST RESULTS
- Normal pH, blood gas, and buffer values
- Base deficit (negative base excess)
- Lactate levels
- SUMMARY AND RECOMMENDATIONS