This is a brief overview of information related to FDA's approval to market this product. See the links below to the Summary of Safety and Effectiveness and product labeling for more complete information on this product, its indications for use, and the basis for FDA's approval.
Product Name: Series 50 XMO Fetal/Maternal Monitor (Model M1350C) with Integrated Fetal Oxygen Saturation Monitoring
Manufacturer: Philips Medical Systems, Inc., Cardiac and Monitoring Systems
Address: 3000 Minuteman Road, Andover, MA 01810
Approval Date: January 3, 2003
Approval Letter: http://www.accessdata.fda.gov/cdrh_docs/pdf2/p020028a.pdf
What is it? This device is an electronic fetal/maternal monitor for use during labor, and it has a new monitoring feature that continuously measures fetal oxygen saturation, the amount of oxygen in the fetus’ blood. The monitor also measures the fetus’ heart rate and the mother’s uterine (womb) contractions. To make the saturation measurement, the Philips’ monitor incorporates the FS14 Sensor from Tyco/Nellcor Puritan Bennett’s recently approved OxiFirst™ Fetal Oxygen Saturation Monitoring System
How does it work? The Nellcor FS14 Sensor (in diagram above) is inserted through the mother’s birth canal into the uterus, where it rests against the fetus’ cheek or temple. Two light emitting diodes (LEDs) in the sensor direct light onto the fetus’ skin. The light is reflected back to a light-measuring device in the sensor, and the reflected light is electronically processed to produce the oxygen saturation measurement. The saturation value is displayed continuously on the monitor’s front panel, along with other measurements. The doctor removes the sensor just before the baby is delivered.
When is this system used? This monitor/sensor system should be used when the fetal heart rate pattern is “non-reassuring”, meaning that there is an indication the fetus may not be getting enough oxygen. The monitor is intended for use on only single (not multiple) fetuses no sooner than 36 weeks after conception. Also, the mother’s water should have broken, with the fetal head in the normal, head-down, position for delivery.
What will it accomplish?
- For the past 30 years, clinicians have relied upon fetal heart rate (FHR) evaluation, an indirect measure, as the primary way to evaluate the fetus’ status during labor. But additional information about fetal oxygen levels may help the doctor to better understand fetal condition during labor.
- In the pivotal clinical study that supported the approval of the OxiFirst™ sensor, the overall rate of cesarean deliveries was unchanged whether or not the new monitor was used. However, use of the monitor did reduce cesarean deliveries for the subgroup of patients who were diagnosed with a non-reassuring fetal status. This finding indicates that clinical understanding of fetal condition during labor improved with the use of this new monitor. FDA has required the sponsor to conduct a post approval study to determine whether cesarean delivery rates are affected as the monitor is introduced into general clinical practice.
When should it not be used? Use of the fetal oxygen saturation monitoring feature is not recommended in patients in the following situations:
- There is documented or suspected placenta previa, in which the organ that nourishes the fetus has developed abnormally in the lower part of the uterus (womb) near the birth canal.
- There is a condition requiring such immediate actions as changing the fetus’ position or inducing delivery.
Summary of Safety and Effectiveness Data (SSED) and Labeling will be available at: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cftopic/pma/pma.cfm?num=p020028