Regina Kulier1
, Julie Hadley2
, Susanne Weinbrenner3
, Berrit Meyerrose3
, Tamas Decsi4,6
, Andrea R Horvath5
, Eva Nagy5
, Jose I Emparanza6
, Sjors FPJ Coppus7,8
, Theodoros N Arvanitis1
, Amanda Burls1
, Juan B Cabello6
, Marcin Kaczor9
, Gianni Zanrei10
, Karen Pierer11
, Katarzyna Stawiarz9
, Regina Kunz11
, Ben WJ Mol7,8
and Khalid S Khan1,2 
1The University of Birmingham, Edgbaston, Birmingham B15 2TG, UK
2Birmingham Women's Hospital, Metchley Park Road, Edgbaston, Birmingham B15 2TG, UK
3Agency for Quality in Medicine, Weglelystrasse 3, 10623 Berlin, Germany
4University of Pécs, Department of Paediatrics, József Attila u. 7, Pécs, H-7623, Hungary
5TUDOR, University of Szeged, Albert Szent-Gyorgyi Medical and Pharmacological Centre, Somogyi Bela ter 1, Szeged, H-6725, Hungary
6CASPe (CASP Espana), Joaquin Orozco 6, 1°-F, 03006 Alicante, Spain
7Academic Medical Center, University of Amsterdam, Department of Obstetrics and Gynaecology, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
8Academic Medical Center, University of Amsterdam, Department of Clinical Epidemiology and Biostatistics, Meibergdreef 9, 1105 AZ Amsterdam, Amsterdam, The Netherlands
9CASPolska, 30-347 Krakow, ul. Wadowicka 3, Poland
10Universitá Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29100 Piacenza, Italy
11Basel Institute for Clinical Epidemiology, Hebelstrasse 10, CH 4031 Basel, Switzerland