Problems with Internal Monitors


Use of an internal monitor is a major risk factor for Chorioamnionitis [1]

Use of IUPC doubles the risk for maternal fever at delivery and for more than 12 hours after delivery [2]

Maternal Fever is a Risk factor for early onset neonatal sepsis [1]

Use of an IUPC and Fetal Scalp Electrode doubles the risk for delivery by C-section [2]

Routine use of an IUPC should be avoided due to increased risk of maternal fever [2]

15-20% of the 4 million deliveries annually in the United States are monitored with an intrauterine pressure catheter.[3]

The Risks and Benefits of Internal Monitors in Laboring Patients

Harper LM, Shanks AL, Tuuli MG, et al. The Risks and Benefits of Internal Monitors in Laboring Patients. Am J Obstet Gynecol 2013; 209:38. e1-6

“Intrauterine pressure catheters (IUPC) and fetal scalp electrodes (FSE) are commonly used devices for intrapartum monitoring and management. Although the internal monitors used are sterilely packaged, they travel through the vaginal canal into the uterine cavity, providing a potential pathway for contamination and ascending infections. Studies are conflicting on whether or not internal monitors are associated with maternal and neonatal infections, but amniotic fluid specimens collected after IUPC insertion have been found to be contaminated with bacteria in 50% of subjects. Additionally, numerous case reports exist of scalp abscesses after monitoring with FSE, and one case control study of infants with GBS sepsis suggest that monitoring with FSE may be associated with a greater risk of death.

Because the IUPC can be used to calculate Montevideo units and adequacy of contractions, they are frequently placed when labor dystocia is a concern. However, randomized control trials comparing the use of internal and external monitors for labor management have not demonstrated a decrease in the risk of cesarean when internal monitors are used, although they also do not demonstrate an increased risk of infectious morbidities.

In spite of this, the use of internal monitors is widespread. At some institutions, it is routine to place internal monitors at the time of membrane rupture.”


  • The use of IUPC alone or in conjunction with an FSE was associated with increased risk of any maternal fever.
  • The use of an IUPC and FSE together was associated with an increase in the risk of cesarean delivery.
  • IUPC use was associated with an approximately twofold increase in the risk of maternal fever before or after delivery.
  • Maternal fever is associated with labor dystocia, prolonged second-stage, post-partum hemorrhage, meconium-stained fluid, neonatal sepsis, neonatal seizures, and neonatal death.


  • No risk of perforation, maternal fever, placental abruption and fetal scalp damage frequently associated with internal monitors.
  • Unaffected by high BMI.
  • Unaffected by movement.
  • No special training to place.
  • No skin preparation or measurement to apply.
  • No new waveforms to learn.
  • No new monitors to buy.

The TrueLaborTM with LaborTrackTM Technology has proven itself in head-to-head comparisons with IUPC, FSE and Fetal Doppler.