Application of fiberoptics to the clinical measurement of intra-uterine pressure in labor.

In the present report we describe a new technique for monitoring intra-uterine pressures during labor. The method utilizes a fiberoptic pressure transducer which is both accurate and stable. The pressure sensor is located at the catheter tip thus eliminating hydrostatic errors during monitoring. At body temperature the catheter is soft and flexible and represents no harm to the fetus. The membrane is housed in a metal dome with large lateral apertures. This arrangement greatly reduces the possibility of blockage. A comparison was made between recordings from the fiberoptic pressure transducer and those from a fluid-filled catheter implanted simultaneously in non-selected subjects during labor. Close agreement was obtained in the majority of cases. Large discrepancies between the two techniques were assumed to reflect the fact that the precise measuring point is not identical in each system. To date, recordings have been made in 52 parturients with no problems with insertion of the device and without any indication of equipment malfunction.