A Safer Pre-Natal Diagnosis Using Free DNA in Maternal Blood

Inclusion Criteria: * Patient/subject is willing and able to give informed consent for participation in the study. * Female, aged 16 years or above. * Currently pregnant at time of entry to the study. * Pregnancy having been identified as 'high-risk' by screening test. Exclusion Criteria: * The patient/subject may not enter the study if ANY of the following apply: * The participant herself has Down's Syndrome or other chromosomal abnormality. * Children under 16 * Adults with learning disabilities * Adults who are unconscious or very severely ill * Adults who have a terminal illness * Adults in emergency situations * Adults suffering from a mental illness * Adults with dementia * Prisoners * Young offenders * Adults who are unable to consent for themselves * Any person considered to have a particularly dependent relationship with investigators