Michael J Sinosich has completed his PhD on Trophoblast Physiology and PAPP-A. His research interests include non-invasive assessment of fetomaternal wellbeing. He is the Director of Prenatal Testing (DHM Pathology) and serves as Consultant at Pictor Ltd, a developer and manufacturer of multiplexed microELISA assay platform. He has published/presented numerous papers in reputed journals and holds several patents.
Prenatal screening is the process by which we identify a population of pregnancies considered at increased risk for a disorder, such as, trisomy 21. Whilst some screens may be clinically more efficient at detecting targeted abnormalities, it should not be forgotten that, prior to initiation of clinical management, ALL abnormal screens should be followed with diagnostic investigations. In this presentation are detailed four case studies which highlight the need for vigilance and caution.
1. Case 1: False Positive cfDNA 2. Case 2: False Negative cfDNA
CFTS Risk: Tri 21 = 1/69366 CFTS Risk: Tri 21 = 1/5
cfDNA = Tri 13 (High Risk) cfDNA = Low risk
Invasive Testing: 46XX Invasive Testing: 47XX + 21
3. Case 3: Fetal Development 4. Case 4: False Negative cfDNA
CFTS Risk: Tri 21 = 1 / 28 CFTS Risk: Tri 21 = 14170
cfDNA = Low risk cfDNA = Low risk
Invasive: 46XX Invasive: 69XXX
Diagnosis: Skeletal dysplasia + FGR
The above 4 cases highlight the nature of screening,
ie., identifying an at risk population requiring definitive investigation. The
above cases also demonstrate that to maximise screening efficacy, we need to
incorporate complementary screening modalities. Hence, early pregnancy
screening programs should include feto-placental biochemistry, extracellular
DNA and ultrasonography.