From the Guidelines
Intrauterine Pressure Catheter (IUPC) is indicated for accurate monitoring of uterine contractions during labor, especially when external monitoring is inadequate or unreliable, as it provides more accurate readings of contraction intensity and frequency compared to external monitoring 1. When considering the use of IUPC, the following scenarios are typically taken into account:
- External monitoring is difficult, such as in obese patients
- There is a need for precise contraction strength measurement
- Labor augmentation with oxytocin is required
- There are concerns about uterine rupture in patients with previous cesarean sections The procedure is typically performed when cervical dilation is at least 2-3 cm, and after the amniotic membranes have ruptured. To perform IUPC placement:
- Explain the procedure to the patient and obtain consent
- Use sterile technique
- Insert the catheter through the cervix between contractions
- Advance it until resistance is felt
- Connect the catheter to the monitoring system It is essential to weigh the benefits of IUPC against the potential risks, such as infection, and use it judiciously, as supported by the American Family Physician guidelines 1. Key points to consider when using IUPC include:
- Accurate assessment of contraction strength and frequency
- Identification of tachysystole, which is defined as more than five contractions in a 10-minute period, averaged over a 30-minute window 1
- Abandoning the term "hyperstimulation" and instead using the term tachysystole, with or without decelerations 1
From the Research
Indication for Intrauterine Pressure Catheter (IUPC)
- The primary indication for IUPC is to monitor uterine contractions during labor, particularly when external tocodynamometry is insufficient or inaccurate 2, 3.
- IUPC is used to measure the frequency, strength, and duration of uterine contractions, providing more accurate information than external tocodynamometry 2, 4.
When IUPC is Performed
- IUPC is typically performed during the induction or augmentation of labor with oxytocin, or to verify adequate uterine contractions to support the diagnosis of arrest of labor 3.
- However, some studies suggest that IUPC may not be necessary for these indications, as external tocography or other non-invasive methods may be sufficient for clinical management of labor 3, 5.
- IUPC may be used in cases where accurate measurement of uterine activity is crucial, such as in high-risk pregnancies or when fetal distress is suspected 2, 6.
Potential Risks and Limitations
- IUPC may cause fetal complications, such as blood loss and signs of fetal distress, particularly if the catheter is not placed correctly or if it lacerates an arteriovenous anastomosis in the membranes 2.
- Transducer-tipped IUPCs may record elevated basal uterine pressures due to measurement of hydrostatic pressures within the uterus, which can lead to inaccurate readings 6.
- The use of IUPC has not been proven to have a positive effect on maternal or neonatal outcomes, and its value is diluted by the potential risks and limitations associated with its use 3.