A randomized controlled trial to compare three types of fetal scalp electrode

Objectives To compare three scalp electrodes in respect of need for reapplication, trace quality and scalp trauma. Design Randomized controlled trial. Setting Maternity Unit, Royal Berkshire Hospital, Reading. Participants 780 women in labour at term, with cephalic fetal presentation, deemed to require electronic fetal heart rate monitoring using a scalp electrode. Interventions Three types of fetal scalp electrode: Rocket-Rolon (double-helix spiral); Hewlett-Packard (double-helix spiral); and Surgicraft-Copeland (clip). Main outcome measures Need for more than one electrode; reason for replacement; trace quality; scalp trauma; direct financial costs. Results Reapplication was significantly least likely in the Surgicraft-Copeland group (odds ratio vs Hewlett-Packard = 0.61, 95% CI 0.41–0.90; odds ratio vs Rocket-Rolon = 0.43, 95% CI = 0.29.0.62). This reflected a much lower rate of replacement because of detachment. The Hewlett-Packard was, however, least likely to be replaced because of poor trace quality. Interpretable traces were equally common, but trace quality tended to be superior in the Hewlett-Packard group. There was no serious scalp trauma. Difficulty removing the electrode was least often reported in the Hewlett-Packard group, and a mark on the scalp persisted least often in the Rocket-Rolon group. Conclusions The Surgicraft-Copeland performed the best overall, and particularly in respect of attachment to the scalp. It appears to be the electrode of choice of the three tested.