EDITORIAL COMMENT: Recently we have accepted a number of papers on trial of scar because of the importance of avoiding unnecessary repeat Caesarean sections. This paper reports impeccable results from Singapore but readers should heed the authors' warnings regarding the need for careful assessment before and during labour, especially when augmentation with oxytocin is employed. In this series trial of labour was permitted when the previous Caesarean was indicated for by cephalopelvic disproportion. It is not enough to monitor labour electronically in such patients — when uterine rupture occurs it can do so suddenly without warning deterioration in fetal condition — an experienced clinician should review these patients regularly during labour, especially when oxytocin augmentation is planned because of uterine dysfunction. Cephalopelvic disproportion may be unrecognized particularly if the patient is obese. In this series the incidence of scar dehiscence was 1.4% (3 of 207) in patients who had a trial of labour; all 3 cases were associated with oxytocin augmentation of labour, and 2 of the 3 laboured for longer than 12 hours (table 6). It is also worth noting that vaginal delivery was achieved in only 2 of 14 mothers who had a trial of labour when birth‐weight was more than 4,000 g (table 5). Note the authors takeaway message that the trial of scar finesse in their institution achieved a reduction of 2% in the overall Caesarean section rate. Note also that in this series, which has acceptable results, 90% of patients allowed a trial of scar had spontaneous onset of labour. Summary: Of 305 patients with a previous lower segment Caesarean section scar admitted over a 28‐month period, 207 were allowed a trial of labour. A successful trial of labour was achieved in 63.3% of patients with a recurrent indication and 73.4% with a nonrecurrent indication. Of 75 patients who received oxytocin for augmentation and 22 for induction of labour, 70.5% achieved vaginal delivery. This was similar to the vaginal delivery rate in patients who did not require augmentation in induction. Three cases of scar dehiscence occurred in patients who had oxytocin, but in whom the recommended management protocol was ignored. The events that led to these 3 dehiscences is described. Analysis of birth‐weights revealed a trend towards more repeat Caesareans with increasing birth‐weight beyond 2,500g. This was especially reflected by the higher emergency Caesarean section rate in those who had a trial of labour. A trial of labour in patients with a previous Caesarean scar is safe, and can be allowed even in patients who had the previous Caesarean for cephalopelvic disproportion, although malpresentation and obvious disproportion must be excluded. Judicious use of oxytocin for a limited period of time should help in reducing the number of repeat Caesarean sections.
|Number of pages||6|
|Journal||Australian and New Zealand Journal of Obstetrics and Gynaecology|
|Publication status||Published - 1989|