As of April 12, 2022, Spectrum Health Laboratory will no longer add microbiology cultures to placental tissues received based on paper requisition forms.
Viral and bacterial cultures from placental tissue are rarely clinically beneficial and are no longer the gold standard diagnostic approach due to the relative insensitivity of culture methods.
If viral studies are desired (possible indications could include known CMV exposure with positive IgM or intrauterine fetal demise at < 28 weeks), then molecular testing is the recommended diagnostic approach. HSV and CMV PCR tests may be ordered in Epic.
• Herpes Simplex 1/2 Qualitative PCR, Tissue (LAB1230413)
• Cytomegalovirus (CMV) Qualitative PCR, Tissue (LAB1230291)
Bacterial cultures are challenging to interpret since they typically grow normal genital flora and histopathological analysis used to diagnose acute chorioamnionitis correlates poorly with growth from bacterial placenta cultures. If indicated, culture and PCR tests may be ordered in Epic.
• Metamycoplasma hominis, Molecular Detection, PCR, Varies (LAB848)
• Ureaplasma species, Molecular Detection, PCR, Varies (LAB848)
Placenta tissues sent to the lab in formalin are not acceptable for PCR or culture orders.
