Approach Considerations

The first step of intrauterine pressure catheter placement is examination of the cervix and presenting part. The cervix must be adequately dilated to place the catheter, at least 1-2 cm.

The tip of the firmer plastic introducer, which contains the intrauterine pressure catheter, is inserted just through the cervix into the amniotic space.

Once the end of the introducer is appropriately positioned, the practitioner’s examining hand holds the introducer in place while the other hand is used to advance the pressure catheter through the introducer into the amniotic space about 10-12 cm. The catheter should thread easily. With correct placement, clear or blood-tinged fluid will be seen within the lumen of the catheter. If blood or no fluid returns, the catheter is likely located between the membranes and endometrium (extraovular), and it should be withdrawn and repositioned.

Once correct position is confirmed, the catheter is farther advanced until the “stop” marking on the catheter is located at the introitus. The introducer is then removed while the catheter is held in place to prevent its inadvertent removal. The catheter is then secured to the inner thigh and attached to the cable.^[9]

Intrauterine pressure catheters are removed by simply pulling gently on the catheter.

Occasionally, the catheter does not advance easily through the introducer or may be felt coiling just past the cervix, likely because the catheter is being blocked by a fetal part. The introducer should be held in place while the catheter is withdrawn. The introducer should then be rotated around to a different position on the presenting part and advanced again. If frank blood returns through the catheter, it has likely been incorrectly placed in the extraovular space. The catheter and introducer should be withdrawn and repositioned while the patient is closely monitored for continued bleeding.