He trained in fetal medicine in Leuven (Belgium), St George’s Hospital London (UK), Leiden (Holland) and attended the programme at Children’s Hospital Philadelphia (PA, USA). He established the Eurofoetus consortium, which is dedicated to the development of instruments and techniques for minimally invasive fetal and placental surgery. The Leuven Fetal Medicine Team focuses on antenatal modulation of lung development, e.g. for pulmonary hypoplasia due to congenital diaphragmatic hernia (CDH) as well as for bronchopulmonary dysplasia. He has headed several clinical studies dedicated to the prenatal prediction of survival of fetuses with isolated CDH using genetic testing, ultrasound and fetal MRI imaging. He developed a percutaneous method for fetoscopic placement of a balloon into the fetal trachea (FETO). In a European task force together with the University of Barcelona (Hospital Clinic) and London (King’s College Hospital) the team performed over 200 such procedures by 2009.