Presentation: Patient with a previous pregnancy or baby affected by a genetic condition

A 24-year-old woman discloses at eight weeks pregnant that she had opted to terminate a previous pregnancy. In that previous pregnancy, a genetic condition was diagnosed at 15 weeks’ gestation following chorionic villus sampling.

• When a previous genetic condition has been identified in a previous pregnancy and a genetic variant has been identified.
• When there are structural anomalies in a current pregnancy.
• When there is a family history of a genetic condition.

• Collect a detailed family and personal history from the couple.
• Refer to clinical genetics for review by a clinical geneticist or genetic counsellor.
• Refer to a high-risk maternity unit for obstetric review. The couple may need referral to your local fetal medicine unit and/or multidisciplinary discussion with the clinical genetics team.
• The clinical genetics team will review the NHS England National Genomic Test Directory eligibility criteria to determine which tests are available to your patient. The directory itself provides a list of all available tests.
  • For those working within NHS Wales, please consult the All Wales Medical Genomics Service website for information on how to arrange testing.
• The clinical genetics team will decide which testing best suits the needs of the patient and/or family. This may include testing previous pregnancies from which tissue and/or DNA is available, or, if a specific diagnosis is suspected, testing the parents.
• If an invasive test is required in the current pregnancy, an amniocentesis or chorionic villus sample or fetal blood sample (in an EDTA tube) is required. For many of the tests (particularly whole genome and exome sequencing), parental samples are also needed or are helpful. Please refer to your local Genomic Laboratory Hub for details of test request forms and where to send samples.
• A record of discussion form, or another appropriate local consent form, is required for testing.
• Information about patient eligibility and test indications was correct at the time of writing. When requesting a test, please refer to the National Genomic Test Directory to confirm the right test for your patient.

For clinicians

• NHS England: National Genomic Test Directory