?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Vale%2C+SH&rft.aulast=Vale&rft.aufirst=SH&rft.date=1+July+2020&rft.atitle=Antenatal+screening+for+Down%E2%80%99s+syndrome%3A+Revised+nuchal+translucency+upper+truncation+limit+due+to+improved+precision+of+measurement&rft.title=Journal+of+Medical+Screening&rft.genre=article