Do biphasic uterine contractions imply poor uterine function?

In a retrospective study of 362 cardiotocographic recordings of primigravidae in labour we found 8% biphasic or coupled uterine contractions. In augmented labour, biphasic contractions occurred almost twice as often as in spontaneous and induced labour. The duration of labour complicated with biphasic contractions was increased significantly in all types of labour. Therefore biphasic contractions may reflect uneffective uterine function. Contrary to other studies, the appearance of biphasic contractions showed no correlation with epidural analgesia and the incidence of instrumental deliveries or caesarean sections was not increased.