The objective of the “Fetalproject2010” is to advance our knowledge in fetal medicine. We focus on pulmonary hypoplasia (PH) in congenital diaphragmatic hernia (CDH) and its relatively new prenatal treatment option, tracheal occlusion (TO). TO prevents egress of pulmonary fluid, thus triggering lung growth. Yet, the procedure is invasive, with main risks premature rupture of membranes and preterm delivery. The question remains as to the optimal occlusion period. We aim to investigate the effects of TO at distinct phases of lung development in the nitrofen (NF) rat. Our results will provide a scientific basis for timing of TO in human CDH fetuses. Patients after fetal surgery are at high risk for tocolysis. One drug frequently used is nifedipine, which inhibits airway small muscle (ASM) contractions in vitro. ASM are believed to be crucial for lung development. We plan to study the impact of nifedipine application on hypoplastic lungs ±TO in the NF rat. Our results will demonstrate potential safety issues. Few centers, including the two host institutions, offer fetal surgery such as TO. We aim to investigate with questionnaires how couples are affected psychologically by interventions. Our results will help to identify the distinct needs of these parents and to tailor support. MRI-spectroscopy (MRS) and fetal magnetoencephalography (fMEG) offer new non-invasive methods to study fetal fluid composition, organ function and development. CDH is associated with altered levels of e. g. vitamin A and decreased cerebral perfusion, the functional impact of the latter is unknown. We aim to investigate the potential of MRS and fMEG in studying lung development as well as brain activity in fetuses with CDH. These results will help to define new markers and methods for diagnostic and prognostic purposes in fetuses with CDH. This grant will help to reintegrate an experienced researcher coming from KU Leuven, Belgium, into the new host organization, University Tübingen, Germany.