Fetal Pulse Oximetry Trial (FOX)

Information on fetal well-being during labor is of great importance to the managing
physician. The current use of the fetal heart rate monitor provides some information on fetal
condition, and is the primary tool used to determine if immediate operative delivery is
required. The fetal pulse oximeter can provide additional information regarding fetal oxygen
saturation.

Intervention: A fetal oxygen saturation sensor is placed in the uterus, between the fetal
cheek or forehead and the uterine wall. In half of the patients, the managing physician will
have access to fetal oxygen saturation and fetal heart rate monitoring. In the other half of
the patients, labor will be monitored by fetal heart rate alone.

Study hypothesis: The additional information provided by the use of the fetal pulse oximeter
will reduce the chances of a cesarean delivery. The primary outcome is cesarean section for
any indication and secondary outcomes are cesarean delivery for non-reassuring fetal heart
rate or dystocia, and neonatal morbidity.

Inclusion criteria:

- Nulliparous

- Singleton, cephalic pregnancy

- Gestational age at least 36 weeks, 0 days

- Cervical dilatation >= 2 cm

- Station -2 or below (5ths scale)

- Ruptured membranes

- Internal monitoring devices placed

Exclusion criteria:

- Need for immediate delivery

- Planned cesarean delivery

- Cervical dilatation > 6 cm

- Known fetal anomaly or demise

- Multifetal gestation

- Maternal fever

- Placenta previa

- Previous uterine surgery

- Active HSV infection

- Known HIV or hepatitis infection

- Diabetes requiring insulin

- Heart disease requiring medication

- Known chronic renal disease

- Enrollment in another labor study