We read with interest the retrospective review of vaginal delivery after three or more caesareans by Cahill et al.1 We are concerned that the results of this study may influence clinical practice and lead to inappropriate obstetric management. The results of this study suggest that it is reasonable and safe to allow women to deliver vaginally after multiple caesarean sections despite the known and documented risks that fit with the biological behaviour of uterine scar tissue. The authors state that nearly 10% of all women who had had three or more caesareans opted for a vaginal birth despite the inherent, and significant, risks that would have been posed to both mother and baby. With the knowledge base at the time of this study, the authors have not confirmed what counselling was given to these mothers about the serious risks involved – particularly those associated with induction or augmentation of labour, which took place in over one-third of the vaginal birth after caesarean (VBAC) mothers. Furthermore, several studies2–4 have already reported the risk of placenta praevia and placenta accreta in this group of women, which rises significantly after a third caesarean such that those women who have a placenta praevia will incur a 61% risk of placenta accreta.4

We note that the authors reported an increase (non-significant) in maternal morbidity in the elective caesarean group but have not reported either maternal or fetal morbidity details in the women who failed in their VBAC attempt – approximately 20% of the VBAC group. We would assume that these women underwent emergency caesarean sections for a variety of reasons that could include uterine dehiscence and incomplete rupture. It would not be unreasonable to assume that these women suffered significant morbidity in terms of blood loss and operative complications as well as fetal compromise.

We are also concerned that neonatal well-being data are absent from the study and should have been included in one of the primary endpoints. This information is essential to complete the definition of a ‘successful VBAC attempt’.


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