A Randomized Trial of Fetal ECG ST Segment and T Wave Analysis as an Adjunct to Electronic Fetal Heart Rate Monitoring (STAN)

Principal Investigator: Michael Varner
Keywords: Pregnant , Labor and Delivery , Full Term Pregnancy Department: Maternal-Fetal Medicine
IRB Number: 00040760 Co Investigator:  
Specialty: Maternal-Fetal Medicine
Sub Specialties:
Recruitment Status: Completed

Contact Information

Kim Hill

Brief Summary

Fetal ECG analysis of the ST segment (STAN) is now FDA-approved and clinically available in the United States as an adjunct for the interpretation of electronic fetal heart rate patterns. There have been a number of randomized controlled trials as well as observational studies in Europe documenting utility of this modality in terms of reducing fetal acidosis at birth, and decreasing the need for operative vaginal delivery. However, despite these endorsements, there remain concerns with the application of the technology to the United States. None of the randomized trials were performed in the United States where patient case-mix and obstetrical practice, such as the use of fetal scalp pH, differ from Europe, which may affect the impact of this technology on perinatal outcomes. Moreover, the results of the European studies are not uniformly positive.

This protocol describes a randomized controlled trial of the STAN technology as an adjunct to electronic fetal heart rate monitoring versus fetal heart rate monitoring alone. The FDA has determined that this device is exempt from IDE requirements.

Inclusion Criteria

1. Singleton, cephalic pregnancy with the intention of a vaginal delivery. A twin pregnancy reduced to singleton (either spontaneously or therapeutically) before 200 weeks by project gestational age is acceptable.

2. Gestational age at randomization at least 36 weeks 1 day, by project gestational age. No upper limit is specified.

3. Cervical dilation of at least 2 cm and no more than 7 cm. A patient with cervical dilation less than 2 cm may be screened but the patient must have documented cervical dilation of at least 2 cm before randomization. The 7 cm upper limit will ensure an adequate amount of time for monitoring and will allow inclusion of patients in the active phase of labor.

4. Ruptured membranes. A patient with intact membranes may be screened and consent may be requested, but membranes must be ruptured and the fetal STAN electrode must be in place before randomization.

Exclusion Criteria

1. Multifetal gestation. This does not include a fetal demise in twin gestation before 20 weeks by project gestational age.

2. Planned cesarean delivery

3. Need for immediate delivery

4. Absent variability or sinusoidal pattern at any time, or a Category II fetal heart rate pattern with absent or minimal variability in the last 20 minutes before randomization. The categories are specified in the 2008 NICHD guidelines on electronic fetal monitoring.

5. Inability to obtain or maintain an adequate signal within 3 trials of electrode placements.

6. Occurrence of any ST event during attempt to obtain adequate signal.

7. Patient pushing in the first stage of labor.

8. Known major fetal anomaly or fetal demise

9. Previous uterine surgery (except dilation and curettage). This includes previous cesarean delivery.

10. Placenta previa on admission (any degree) because of the likelihood of cesarean delivery. This does not include low-lying placenta.

11. Maternal fever  38 C (100.4 F) or suspected chorioamnionitis at any time since admission to Labor and Delivery

12. Active HSV infection, because of the likelihood of cesarean delivery and fetal infection with fetal scalp electrodes

13. Known HIV or hepatitis infection

14. Other maternal or fetal contraindication for using the STAN monitor, such as fetal arrhythmia, fetal coagulation disorder, or use of transcutaneous electrical nerve stimulation (TENS) analgesia, or for using a fetal scalp electrode.

15. Enrollment in another labor study which may affect the interpretation of the FHR or affect the decision on how or when to deliver.

16. Participation in this trial in a previous pregnancy.

17. No certified or authorized provider available according to Section 4.1 – Training and Certification – of the main protocol.