[Evaluating pulse oximetry in the fetus. Case control study for detection of undesirable complications]

Fetal pulse oximetry (PO) requires basically continuous contact of a transcervically positioned oxisensor with fetal skin. To improve signal quality adjustments of the oxisensor may be necessary. Against this background it was our intention to find out if this intrauterine device causes an increase in fetal or maternal infectious morbidity.

We enrolled into this prospective trial 63 deliveries monitored by a blinded fetal pulse oximeter (N 400, Nellcor Inc. Pleasanton, CA) and a fetal oxisensor (FS 10; lambda = 660 + 890 nm). The control group of similar gestational age was formed by 63 chronologically following deliveries under responsibility of the same physician to reduce personal bias of obstetrical management.

While the obstetrical risk factors (non-reassuring FHR i.e.) were significantly higher in the group with PO, gestational age, number of operative deliveries, pH of umbilical cord and Apgar score ratings did not show any significant difference. The number of post partum anaemias and local or systemic infections were identical (3 in each group). Seven neonates of the PO group had to be transferred to NICU versus 12 in the control group. The duration of antibiotic treatment, mechanical ventilation or phototherapy did not differ significantly; neither did the number of neonatal infections.

In the group of fetuses monitored by fetal pulse oximetry there was no increase in fetal or maternal infectious morbidity. There was no evidence of adverse side effects which might limit the advantage of continuous oxygen saturation monitoring.