Detection of monkeypox virus DNA in placental tissue and amniotic fluid associated with acute fetal compromise without confirmed vertical transmission: a case report

Mpox during pregnancy is uncommon, and evidence concerning placental involvement, fetal effects, and vertical transmission remain limited, particularly in African settings. A 32-year-old Ugandan woman, gravida 3 para 2, presented at 38 weeks and 3 days of gestation with fever and a generalized vesiculopustular rash following household exposure to a suspected mpox case. Maternal mpox was confirmed by polymerase chain reaction testing of skin-lesion specimens. Monkeypox virus DNA was also detected in amniotic fluid and placental tissue. Although the maternal skin lesions subsequently showed evidence of healing and her vital signs remained stable, on day 13 after symptom onset, she reported absent fetal movements. Ultrasonography demonstrated a biophysical profile score of 4/8, with absent fetal tone and body movements but adequate amniotic-fluid volume. An emergency cesarean section was performed approximately 5 h after identification of fetal compromise. A live female neonate weighing 2.89 kg was delivered, with Apgar scores of 9 and 10 at 1 and 5 min, respectively. The neonate had no skin or mucosal lesions and remained clinically stable. Neonatal skin and oral specimens collected 12 h after birth tested negative for monkeypox virus by polymerase chain reaction. This case documents the detection of monkeypox virus DNA in placental tissue and amniotic fluid in association with acute fetal compromise, without confirmed neonatal infection. A causal relationship between maternal mpox, placental viral DNA detection, and fetal compromise cannot be established from a single case. Nevertheless, the case highlights the importance of close fetal surveillance and coordinated obstetric, neonatal, infectious-disease and infection-prevention management of pregnant patients with mpox.