title: Screening for fetal trisomy 21: voluntary registration of pregnancy outcome is invalid.
authors: W J A
authors: WJ
authors: Gyselaers
authors: D P M
authors: DP
authors: Stoop
authors: C D Y J
authors: CD
authors: Van Holsbeke
authors: E J H
authors: EJ
authors: Van Herck
authors: D P L
authors: DP
authors: Straetmans
authors: A J
authors: AJ
authors: Vereecken
authors: W U A M
authors: WU
authors: Ombelet
authors: J G
authors: JG
authors: Nijhuis
mesh_terms: D000328:Adult; D001530:Belgium / Q000453:epidemiology; D004314:Down Syndrome / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D011247:Pregnancy; D011256:Pregnancy Outcome; D012042:Registries; D035141:Voluntary Programs