No reason to doubt standard of prenatal diagnosisBMJ 1996; 312 doi: https://doi.org/10.1136/bmj.312.7038.1100a (Published 27 April 1996) Cite this as: BMJ 1996;312:1100
- Johanne M Hahnemann,
- Lars O Vejerslev
- Project coordinator Project leader European Collaborative Research on Mosaicism in CVS, Department of Medical Genetics, John F Kennedy Institute, DK-2600 Glostrup, Denmark
EDITOR,—As participants in the European collaborative research on mosaicism in chorion villus sampling, we wish to comment on Claus Hojbjerg Gravholt and colleagues' paper on the prenatal and postnatal prevalence of Turner's syndrome.1 The authors claim to have assessed the validity of prenatal diagnosis, but their conclusions on the magnitude of the predictive value are based on incomplete data.
Calculation of the predictive value requires that every karyotype obtained on prenatal diagnosis can be classified as false …