1. Introduction to prenatal diagnosis
Kathelijn Keymolen

2. Goals of PND
To inform couples about the risk of a birth defect / genetic disorder in their pregnancy
To give the couples the information to make an informed decision

3. Counseling before PND
Uptake in prenatal diagnosis is the choice of the woman/ couple
Non-directive counseling by geneticist, genetic counselor, gynecologist ...
Option for psychological guidance in the decision-making process

4. Counseling before PND
Personal and familial history of couple, consanguinity
Carrier testing can be proposed according to prevalence of disorder
Hb chromatography in Asian, African, Mediterranean people
Tay Sachs, ..in Ashkenazi Jewish

5. Counseling before PND Explain Risk for affected fetus
Detected disorders
Risks , limitations of the procedures ( NIPT, invasive PND), general principles about the techniques
Answering time
Decisions to be considered after PND

6. Result of PND Absence of specific condition
Reassurance
Presence of specific condition
Plan treatment/ follow-up (eg adrenogenital syndrome)
Psychological preparation of parents/ family
Termination of pregnancy

7. Result of PND
VUS/ incidental findings/ variable expression/ reduced pentrance
Importance of post-test counseling becomes more important with higher complexity of tests

8. Reasons for performing PND
Advanced maternal age
≥ 35 years
Risks for aneuploidy at amniocentesis
1/250 at 35y
1/200 at 36y
1/70 at 40y
1/25 at 44y

9. Reasons for performing PND
Psychosocial reasons
Reassurance in couples without an increased risk
“NIPT for everybody”
Medical staff
Other caregivers
Positive family history but low recurrence risk

10. Reasons for performing PND
History of chromosomal anomaly
Previous conceptus with aneuploidy ( eg Trisomy 21) NIPT
Structural/ numerical chromosomal anomaly in a parent ( eg carrier of translocation) INVASIVE PND

11. Reasons for performing invasive PND
Positive non-invasive screening
Ultrasound
NIPT

12. Reasons for performing invasive PND
Specific monogenic condition in family
History of an affected family member
Parent with Marfan
Child with cystic fibrosis
Parent(s) healthy carriers
HbS (AR)
CF (AR)
Fra X (XL)

13. Reasons for performing invasive PND
US anomalies and maternal seroconversion CMV
Fetal anemia
Parvovirus
Rhesus immunization

14. PND Evolving landscape ~ available techniques ~ reimbursement criteria
~ societal demands/ expectations

15. PND
Multidisciplinary and dynamic approach
Patient-centered