Fetal pulse oximetry doesn't improve outcomes

Journal of Family Practice, April, 2007

* Clinical question

Does knowledge of fetal oxygen saturation in conjunction with electronic fetal monitoring lead to fewer cesarean deliveries or improved neonatal outcomes?

* Bottom line

No, fetal pulse oximetry as an adjunct to continuous electronic fetal monitoring does not decrease the cesarean delivery rate or improve neonatal outcomes.

Level of evidence

1b: Individual randomized controlled trials (with narrow confidence interval)

Study design

Randomized controlled trial (single-blinded)

Funding

Government

Allocation

Uncertain

Setting

Inpatient (ward only)

Synopsis

In May 2000, the US Food and Drug Administration granted conditional approval for a device to monitor fetal oxygen saturation (OxiFirst Fetal Oxygen Saturation Monitoring System, Mallinckrodt Nellcor Perinatal Business, Pleasanton, Calif). The FDA required further studies to ascertain whether use of the device results in fewer cesarean deliveries and improved neonatal outcomes.

This study of 5431 women in labor was conducted to address this need. Nulliparous women with singleton pregnancies at term, in cephalic presentation, and 2- to 6-cm cervical dilatation were recruited on admission to participating labor and delivery units. Women were excluded if they were planing on a cesarean delivery or had a fever, HIV, hepatitis, renal or cardiac disease, diabetes, or a failed attempt to insert the sensor device.

All women in the study had the pulse oximetry sensor devices inserted and were randomized to 1 of 2 groups: one with clinician access to the fetal oxygen saturation data, and one without access.

There were no differences in the overall cesarean rates between open and masked groups (26.3% vs 27.5%) or for the indication of nonreassuring fetal heart rate (7.1% vs 7.9%). A subgroup analysis looked at those women with nonreassuring fetal heart rate patterns, as recorded before randomization and categorized according to well-defined criteria used in previous studies. This subgroup had similar results between open and masked groups (31.1% vs 30.5% cesarean deliveries).

There were no differences between groups in neonatal outcomes. A composite outcome of a 5-minute Apgar score of less than 4, umbilical artery pH less than 7.0, seizures, intubation in the delivery room, stillbirth, neonatal death, and intensive care admission for more than 48 hours was 3.2% vs 3.4%.

FAST TRACK

Knowing fetal oxygen saturation rates had no impact on C-section rate or neonatal outcomes

Bloom S, Spong CY, Thom E, et al, for the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Fetal pulse oximetry and cesarean delivery. N Eng J Med 2006; 355:2195-2202.]