Nickelsen C, Weber T
Br J Obstet Gynaecol. 1986 Dec;93(12):1272-5. doi: 10.1111/j.1471-0528.1986.tb07865.x.
The influence of electrode compression by the cervix on transcutaneous CO2 measurements (tc-Pco2) was studied during 20 deliveries by simultaneous measurements with two electrodes, one positioned under the cervical edge and the other free of the cervix. At a cervical dilation of less than 8 cm, significantly higher values were measured by the electrode exposed to cervical compression, and tc-Pco2 fluctuations with uterine contractions were observed. This study confirms that the tonsure effect usually does not interfere with tc-Pco2 monitoring.
