This important paper will be of interest to many list members.

Jane Sandall

Fetal Pulse Oximetry and Cesarean Delivery

Knowledge of fetal oxygen saturation, as an adjunct to electronic fetal monitoring,

may be associated with a significant change in the rate of cesarean deliveries or the

infant’s condition at birth.

We randomly assigned 5341 nulliparous women who were at term and in early labor

to either “open” or “masked” fetal pulse oximetry. In the open group, fetal oxygen

saturation values were displayed to the clinician. In the masked group, the fetal

oxygen sensor was inserted and the values were recorded by computer, but the data

were hidden. Labor complicated by a nonreassuring fetal heart rate before randomization

was documented for subsequent analysis.

There was no significant difference in the overall rates of cesarean delivery between

the open and masked groups (26.3% and 27.5%, respectively; P = 0.31). The rates of

cesarean delivery associated with the separate indications of a nonreassuring fetal

heart rate (7.1% and 7.9%, respectively; P = 0.30) and dystocia (18.6% and 19.2%,

respectively; P = 0.59) were similar between the two groups. Similar findings were

observed in the subgroup of 2168 women in whom a nonreassuring fetal heart rate

was detected before randomization. The condition of the infants at birth did not

differ significantly between the two groups.

Knowledge of the fetal oxygen saturation is not associated with a reduction in the

rate of cesarean delivery or with improvement in the condition of the newborn.