A new device for measuring intrauterine temperature

Objective: We evaluated a new device that uses the intrauterine pressure catheter to measure the maternal temperature in patients who are in labor. Study Design: The study was conducted at two medical centers, Christiana Hospital in Newark, Delaware, and Saint Louis University/St Mary’s Health Center in St Louis, Missouri, from September 1, 1997, to May 2, 1998. An intrauterine pressure catheter with a thermistor sensor in the tip was placed into the uterus after spontaneous rupture of membranes. The intrauterine, oral, and tympanic temperatures were simultaneously obtained immediately after insertion of the intrauterine pressure catheter and then hourly until delivery or the initiation of amnioinfusion. Results: The study comprised 97 patients and 404 temperature readings with a temperature range of 34.7°C to 40.7°C. The normal mean ± SD for the oral, tympanic, and intrauterine temperatures was 36.7°C ± 0.5°C, 36.8°C ± 0.5°C, and 37.3°C ± 0.4°C, respectively. There was a linear relationship among the oral, tympanic, and intrauterine temperatures. All three methods showed a significant increase in mean body temperature after epidural anesthesia. Conclusion: The new device, the intrauterine pressure-temperature catheter, provides a convenient and accurate means of continuously measuring uterine temperature in patients who are in labor and require intrauterine monitoring. (Am J Obstet Gynecol 2001;184:1431-5.)