The fetal heart rate W-sign.

A biphasic fetal heart rate variable deceleration pattern (W-sign) was investigated and found to be significantly associated with a greater length of umbilical cord (73.07 +/- 17.1 cm) than was found in patients without this pattern (56.47 +/- 11.4 cm) during the first stage of labor (P less than .001). The possible etiology of this variable deceleration pattern and its relative benignity are discussed.