RT Journal Article SR Electronic T1 Antenatal Diagnosis of Fetal Abnormalities JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 357 OP 358 DO 10.1136/jmg.29.5.357-c VO 29 IS 5 A1 Tolmie, John YR 1992 UL http://jmg.bmj.com/content/29/5/357.4.abstract AB