THE RELIABILITY OF CATHETER-TIP TRANSDUCERS FOR THE MEASUREMENT OF INTRAUTERINE PRESSURE IN THE 3RD STAGE OF LABOR

In order to assess the reliability of intrauterine pressure measuremen ts in the third stage of labour, catheter-tip transducers were used in 20 women randomly allocated into two groups of 10. In each case in th e first group two catheters were tied together and introduced transcer vically into the uterine cavity after delivery of the placenta. In eac h case in the second group two catheters were inserted independently i nto the same uterine cavity. The active and cumulative active pressure s recorded from the pairs of catheters within each uterine cavity were compared. Comparison of individual active pressure readings from sepa rate transducers revealed good agreement whether the catheters were ti ed together or were seperate. Cumulative active pressure was very simi lar when assessed by each catheter in the same uterus. Intrauterine ca theter-tip transducers can be used reliably to measure uterine activit y in the third stage of labour although there may be minor contraction by contraction differences in recordings of individual active pressur es.