An intrauterine catheter device for monitoring fetal and/or maternal heart rate, including an elongate housing having proximal and distal portions, an array of ECG electrodes on the distal portion and one or more acoustic or other mechanical sensors on the distal portion. A pressure transducer may also be provided on the distal portion. Processor circuitry compares the ECG signal with the output signal of the acoustic sensor to derive fetal and/or maternal heart rate. An intrauterine catheter device is also provided, including a reference electrode on its distal portion, and an array of active electrodes spaced apart from one another on the distal portion. The device may also include a pressure transducer on the distal portion and processor circuitry coupled to the array of active electrodes and/or to the reference electrode for deriving fetal ECG from signals produced by the array of active electrodes. Alternatively, the array of electrodes and acoustic sensors may be provided on a flexible pad that may be secured to the abdomen of a pregnant mother. An intrauterine catheter device is also provided, including a plurality of lumens communicating with a differential pressure transducer provided on its distal portion, and having a zeroing switch on its proximal portion for resetting the pressure transducer in situ.