1. Department of Obstetrics and Gynaecology, Santa Lucia General University Hospital, 30202 Cartagena, Spain
2. Department of Obstetrics and Gynaecology, La Fe University and Polytechnic Hospital, Avenida Fernando Abril Martorell 106, 46026 Valencia, Spain
3. Department of Anesthesiology, La Fe University and Polytechnic Hospital, Avenida Fernando Abril Martorell 106, 46026 Valencia, Spain