Products of Conception Recommendations

When to test?

• After any third trimester fetal demise or stillbirth
• For patients with recurrent pregnancy loss, test products of conception from a second loss

What to order?

First tier:  IFISH for chromosomes 13, 15, 16, 18, 21, 22, X, and Y.  Using this panel, a diagnosis will be made for about 80% of pregnancy losses that occurred because of chromosome abnormalities.

If the IFISH result is consistent with trisomy 16, trisomy 18, 45X, XXX, XXY, XYY, triploidy, or tetraploidy: testing is complete.
 
Second tier:  If the IFISH result is consistent with trisomy 13, trisomy 15, Down syndrome, or trisomy 22: reflex to karyotyping on cultured cells to determine whether the abnormality is due to a free trisomy (sporadic) or an unbalanced Robertsonian translocation (possibly heritable).
OR
Second tier:  If the IFISH result is normal: reflex to a cytogenomic microarray analysis (CMA).
 
If the CMA is normal: testing is complete.
If the CMA is consistent with trisomy 3, trisomy 7, monosomy 4, etc.:  testing is complete.
 
Third tier:  If the CMA is consistent with trisomy 14:  reflex to karyotyping on cultured cells to determine whether the abnormality is due to a free trisomy (sporadic) or an unbalanced Robertsonian translocation (possibly heritable).
OR
Third tier:  If the CMA result shows possibly heritable abnormalities (e.g. paired terminal deletions and duplications suggestive of an unbalanced translocation): G-banded chromosome analysis on cultured cells or subtelomere metaphase FISH would be recommended to confirm the structure of the abnormality, but would not be done reflexively.