1. Gynecology and Obstetrics Section, Department of General Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
2. Centre for Reproductive Medicine, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
3. Embryolab IVF Unit, Thessaloniki, Greece
4. Centre for Reproductive Medicine, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium