Contribution to authorship
DR proposed the subject of this study. NM, MP and CN developed the study design. RR and MK checked the study design and made corrections in their respective areas of expertise: obstetrics and anaesthesia. CN and AS conducted the data collection. MP conducted the data analysis. CN, NM and MP interpreted the data and drafted the manuscript. All authors were involved in reviewing the manuscript. All authors gave approval of the final version of the manuscript.