Study Finds COVID Does Not Linger in Placental Tissue Post-Infection

The researchers sought to determine whether long COVID-like cells would remain in placental tissue.

April 27, 2026

Key Highlights

The study analyzed 12 placentas from women with recent or past COVID-19 infections to assess viral presence and placental health.
No traces of the virus were found in placentas from women who had recovered from COVID-19, even as early as 40 days post-infection.
Structural and inflammatory changes were observed in placentas from recovered women, indicating lingering immune responses rather than active infection.
Active COVID-19 infections in pregnant women were associated with placental inflammation and higher rates of stillbirth and neonatal loss.
Findings suggest that the immune response to COVID-19 may impact placental health even after the virus has been cleared.

A case-control study published in JAMA Network Open found that the virus that causes COVID-19 “does not appear to linger in placental tissue after a pregnant patient recovers from acute infection.” CIDRAP has the news.

The team of researchers analyzed “12 placentas collected at delivery from October 2020 to December 2024” to compare a control group, active cases of acute COVID-19 placentitis (inflammation of the placenta), and pregnancies following maternal recovery from infection. Three of the seven placentas collected from women who had recovered from COVID resulted in stillbirth. As early as 40 days after maternal infection, “no trace of the virus or its genetic material was found in any of the placentas.”

The researchers did observe “structural and inflammatory changes in some of the placentas from women who had recovered from acute infection, suggesting that the body’s immune response to the infection can linger even after the virus has been cleared.”

The virus could also be seen clearly in placental cells from women with active COVID infections at time of collection. Three of the four pregnancies resulted in stillbirth, and the fourth resulted in neonatal loss.