Fetal heart rate patterns during forceps operation.

Abstract

It is currently taught that early decelerations, or type l Dip, are related to the compression of the fetal head in the birth canal, late decelerations, or type 2 Dip, to placental insufficiency and variable decelerations to cord compression. All these patterns are elicited by, and by definition related to, the uterine contractions. With the increasing use of electronic fetal heart rate monitoring these Standard interpretations are currently being challenged, especially by people engaged both in clinical research and active obstetric practice [2,4,17,18,19,21]. As far as early deceleration or type l Dip is concerned, its frequency [2, 3] is surprisingly low in relation to the constant phenomenon(?that supposedly causes it: namely, compression of the fetal head in the birth canal during the uterine contractions. Nor is it more frequent when both uterine activity and the obstacle to the passage of the head are greater, as in cephalo pelvic disproportion. On the other hand, early deceleration can be seen in cases of floating head and intact membranes and also in breech presentation. Finally, the claim that the early deceleration is innocuous needs a thorough revision [2,12a, 23]. Cumculum vitae