1. Department of Reproduction, Genetics and Regenerative Medicine (RGRG), Biology of the Testis (BITE), Vrije Universiteit Brussel (VUB) , Brussels, Belgium
2. Brussels IVF, Universitair Ziekenhuis Brussel (UZ Brussel) , Brussels, Belgium
3. Division of Paediatric Radiology, Department of Radiology, Universitair Ziekenhuis Brussel (UZ Brussel) , Brussels, Belgium
4. Department of Hemato-Oncology, Hôpital Universitaire des Enfants Reine Fabiola (HUDERF), Université Libre de Bruxelles (ULB) , Brussels, Belgium
5. Department of Obstetrics, Gynaecology, Perinatology and Reproduction, Institute of Professional Education, Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University) , Moscow, Russia
6. Division of Paediatric Endocrinology, Department of Paediatrics, Universitair Ziekenhuis Brussel (UZ Brussel), Vrije Universiteit Brussel (VUB) , Brussels, Belgium