Vaginal delivery following caesarean section: a prospective study without radiological pelvimetry.

In a prospective study of trial and labour in 180 secundigravidae who had all previously delivered by caesarian section, 48,8 percent achieved a successful vaginal delivery. The total incidence of scar dehiscence was 2,2 percent, symptomatic scar rupture was observed in 1,1 percent of cases. The perinatal mortality due to trial of labour was 27.7/ 1 000 with scar rupture contributing 11,1/1 000 perinatal deaths. In the patients whose trial of labour failed, significantly fewer women established strong contractions and their babies were also larger. These results were achieved without prior selection of patients according to clinical or radiological pelvimetry. It is suggested that all such secundigravidae should be given a trial of labour without prior selection unless an independent factor indicates the need for an elective caesarean section. Recent reviews have highlighted the success and safety of Trial of Labour (TOL) in patients previously delivered by caesarean section. In the majority of studies reviewed, either clinical or radiological pelvimetry, or both, were used to select those patients who could be allowed to labour from those who could not There is controversy as to whether radiological pelvimetry is useful for these patients because results of studies have been conflicting. Studies in patients without previous caesarean section have shown that radiological pelvimetry is not a useful predictor of Cephalopelvic Disproportion (CPD) in cephalic presentations. There is no inherent reason why it should be more useful in this respect in patients with a previous caesarean section scar. There is also the unnecessary exposure of the foetus to irradiation, which carries the risk of oncongenisis, although this risk is now thought to be low. Previous caesarean section is now the second commonest indication for abdominal delivery in Harare, Zimbabwe. In Zimbabwe as a whole facilities and skills for radiological pelvimetry exist only in the main centres. Elective caesarean section is routinely resorted to in the absence of these facilities, despite lack of evidence that this is safe and appropriate. This study was designed to examine the safety and efficacy of trial of labour without prior radiological pelvimetry for patients in their second pregnancy with one previous caesarean section.