INTRAPARTUM FETAL OXYGEN-SATURATION MONITORING IN CONGENITAL FETAL HEART-BLOCK

Conventional intrapartum electronic fetal heart rate monitoring is not informative in certain fetal conditions because the electronically-mo nitored fetal heart rate pattern is uninterpretable in terms of reflec ting fetal normoxia. Such fetal conditions include various cardiac dys rrhythmias and some central nervous system abnormalities. Difficulties with intrapartum fetal welfare surveillance in such conditions often lead to operative delivery as a precautionary measure. We report 2 cas es of intrapartum fetal oxygen saturation monitoring in the presence o f congenital complete heart block (CCHB), using the Nellcor N400/FS14 oxygen saturation monitoring system. Mean intrapartum fetal oxygen sat uration (FSpO(2)) was 32% (SEM +/- 1%) in the first case and 48% (SEM +/- 0.3%) in the second case. In both cases, vaginal delivery of other wise healthy infants was achieved. Fetal pulse oximetry is a promising new technique which directly measures fetal oxygenation without refer ence to fetal heart rate patterns. It may assist in the intrapartum fe tal welfare assessment in conditions such as complete heart block, the reby helping to avoid otherwise unnecessary operative delivery.