THE EFFECT OF CAPUT-SUCCEDANEUM ON OXYGEN-SATURATION MEASUREMENTS

Summary. Advances in oximetry have allowed the obstetrician to measure oxygen saturation in the fetus with non‐invasive transcutaneous techniques. The influence of caput succedaneum formation on the oxygen saturation results obtained with a pulse oximeter was studied in 30 newborn infants. Caput was associated with a reduced oxygen saturation reading (mean reduction of 15%; P<0.001). This effect is partly due to a true drop in local tissue oxygenation but is exacerbated by a systematic error intrinsic to the physics of spectrophotometry. If continuous intrapartum oximetry is ever to become a part of routine obstetric monitoring then probes that pass through the cervix beyond the caput of the presenting part will be required if erroneously low readings are to be avoided. Copyright © 1990, Wiley Blackwell. All rights reserved