1 Department of Obstetrics, Division of Fetal therapy, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: m.j.a.van_de_sande@lumc.nl.
2 Department of Obstetrics, Division of Fetal therapy, Leiden University Medical Center, Leiden, The Netherlands.
3 Department of Pediatrics, Division of Neonatology, Leiden University Medical Center, Leiden, The Netherlands.