Evaluation of oxygen desaturation events in singleton pregnancies.

Previous investigators have demonstrated that oxygen desaturation may occur in laboring women. The purposes of this study were to identify groups at risk for desaturation and to seek correlation with newborn outcome. Volunteers in labor were evaluated for oxygen desaturation, analgesic exposure, magnesium sulfate administration, and various medical illnesses. Desaturations were noted more frequently in women exposed to narcotic analgesics, sedatives, and magnesium sulfate. A trend toward more desaturations in the women with preeclampsia was noted. Although desaturations related to narcotic analgesics and sedatives are most likely due to hypoventilation, the mechanism in women treated with magnesium sulfate is uncertain. Maternal peripartum desaturations did not result in unfavorable neonatal Apgar scores, cord blood gas measurements, or neonatal oxygen desaturation values, but the staff was aware of the events and prompt treatment was instituted.