Uterine activity in dysfunctional labour and target uterine activity to be aimed with oxytocin titration.

Abstract

Uterine activity was quantified using a transducer tipped intrauterine catheter in 75 nulliparous women with dysfunctional labour. The active contraction area profiles in these women were below the median levels reported for those who had normal progress of labour from our institution. When uterine activity was augmented with oxytocin, 90.7% progressed in labour and delivered vaginally. Six patients (8%) showed poor progress despite good uterine activity and had to be delivered by caesarean section (CS) for failure to progress and signs of cephalopelvic disproportion. The pre- and post-augmentation uterine activity were similar in those who delivered vaginally or by CS and was not helpful in identifying those who had cephalopelvic disproportion. Of the 75 women who had slow progress of labour, 50 had a contraction frequency of less than 1 in 3 min whilst 25 had a minimum frequency of 1 in 3 min or more. All except one in the latter group delivered vaginally when oxytocin was titrated to achieve a contraction frequency of 1 in 2 to 2 1/2 min which were clinically judged to be adequate based on a duration greater than 40 sec. Oxytocin should be titrated to achieve a target contraction frequency of 1 in 2 to 2 1/2 min lasting greater than 40 sec to achieve good obstetric outcome in those with dysfunctional labour.