1 Department of Maternal-Fetal Medicine (ICGON), Fetal Medicine Research Center, BCNatal-Barcelona Center for Maternal-Fetal and Neonatal Medicine (Hospital Clínic and Hospital Sant Joan de Deu), IDIBAPS, University of Barcelona, Sabino de Arana 1, Barcelona, Spain 08028.
2 Department of Maternal-Fetal Medicine (ICGON), Fetal Medicine Research Center, BCNatal-Barcelona Center for Maternal-Fetal and Neonatal Medicine (Hospital Clínic and Hospital Sant Joan de Deu), IDIBAPS, University of Barcelona, Sabino de Arana 1, Barcelona, Spain 08028. Electronic address: fcrispi@clinic.cat.
3 Centre for Biomedical Research on Rare Diseases (CIBER-ER), Barcelona, Spain.