The long-term costs and effects of tubal flushing with oil-based versus water-based contrast during hysterosalpingography

Acknowledgements The authors would like to thank all the participating women, the hospitals and their staff, the research nurses and the staff of the Nationwide Consortium for Women's Health Research (NVOG Consortium; www.zorgevaluatienederland.nl ) for logistical support. Thanks also go to the H2Oil study group collaborators: Nan van Geloven, Jos W. R. Twisk, Peter M. van de Ven and Peter G. A. Hompes for their contributions to this study. The original H2Oil RCT was an investigator-initiated study that was funded by the two academic institutions (AMC and VUmc) of the Amsterdam UMC. The long-term follow-up study and economic analysis, both investigator-initiated studies, were funded by a research grant from Guerbet, France. The funders had no role in study design or collection, analysis or interpretation of the data. Declaration of interest: C.T.P. has received consultancy fees for external work from Guerbet, France. K.D. reports receiving travel and speakers fee from Guerbet. H.R.V. reports receiving consultancy fees from Ferring. M.G. works at the Department of Reproductive Medicine of the Amsterdam UMC (location AMC and location VUmc). Location VUmc has received several research and educational grants from Guerbet, Merck and Ferring. C.B.L. reports speakers fee from Ferring in the past, and his department receives research grants from Ferring, Merck and Guerbet. V.M. reports receiving travel and speakers fees as well as research grants from Guerbet. B.W.J.M. is supported by a NHMRC Investigator grant (GNT1176437). B.W.J.M. has received research grants from Merck and Guerbet. The other authors report no financial or commercial conflicts of interest.Peer reviewedPublisher PD