2. In cooperation with international partners compare data from Denmark and Sweden (partner in Sweden: Eleonor Tiblad, MD, Ph.D, Center for Fetal Medicine, Karolinska University Hospital) and if possible also Saudi Arabia (partner in the Saudi Arabia collaboration: Marianne Juhler, MD, DMSc, Professor, Rigshospitalet, Denmark and Daniele Rigamonti, MD, professor, Chief of Staff, Department of Neurosurgery, John Hopkins University Hospital Aramco Health Care, Baltimore, USA)