Midluteal buserelin is superior to early follicular phase buserelin in combined gonadotropin-releasing hormone analog and gonadotropin stimulation in in vitro fertilization**Supported by a grant from Hoechst Aktiengesellschaft, Frankfurt/Main, Germany.††The following investigators participated in the conduct and analysis of this study: Paul Devroey, Akademisch Ziekenhuis, Vrije Universiteit, Brussels, Belgium; Bengt Fredricsson, Huddinge University Hospital, Huddinge, Sweden; Kertsin Hagenfeldt, Karolinska Hospital, Stockholm, Sweden; David Healy, Prince Henry’s Hospital, Melbourne, Australia; Konrad Lisse, Frauenklinik Charité, Berlin, Germany; Thomas Rabe and Janos Urbancsek, Universitäts-Frauenklinik, Heidelberg, Germany; Joop Schoemaker, Akademisch Ziekenhuis, Vrije Universiteit, Amsterdam, The Netherlands.