Abstract. Electronic FHR‐monitoring is, like monitoring of the heart in adults, combined with artefacts. In the fetus interpretation of artefacts and diagnosis of cardiac disease are facilitated, if the filtered R‐wave is presented simultaneously with FHR. Changes in rate depending on artefacts can be misinterpreted with commercial instrumentations as depending on “fetal distress” which can be avoided with the equipment described in this paper. Filter properties and further reduction of noise are discussed.