Congenital Mpox Syndrome (Clade I) in Stillborn Fetus after Placental Infection and Intrauterine Transmission, Democratic Republic of the Congo, 2008

We report the autopsy pathology findings of a 21-week stillborn fetus with congenital mpox syndrome that oc-curred in the Democratic Republic of the Congo in 2008. The fetus acquired mpox from the mother after intrauter-ine transplacental monkeypox virus transmission. We confirmed monkeypox virus infection in the mother, fetus, and placenta by using a monkeypox virus-specific quan-titative PCR. Subtyping of the virus was not performed, but the mother and fetus were almost certainly infected with the clade I variant that was endemic in the Demo-cratic Republic of the Congo at the time. Risk for intra-uterine infection appears to differ between virus clades, but clinicians should be aware of potential for intrauterine monkeypox virus transmission among pregnant persons during ongoing and future mpox outbreaks.