Maternal and neonatal mpox in Nigeria: a multicentre case series highlighting diagnostic challenges, transmission pathways, and neonatal outcomes

Abstract Background Mpox during pregnancy and the neonatal period is uncommon, and evidence regarding maternal clinical presentation, neonatal acquisition, and pregnancy outcomes remains limited, particularly in endemic African settings. Data on maternal–neonatal pairs infected with Clade IIb monkeypox virus (MPXV) are especially scarce. We describe the clinical characteristics, diagnostic challenges, potential transmission pathways, and outcomes of three mother–infant pairs managed at hospitals in southern Nigeria. Case presentation We conducted a retrospective multicentre case series involving three mothers with probable mpox during late pregnancy and their three neonates with laboratory-confirmed mpox managed at two tertiary teaching hospitals and one private specialist hospital in southern Nigeria. All mothers developed acute febrile illnesses during the third trimester or immediately before delivery. Two presented with characteristic vesiculopustular eruptions, whereas one experienced a self-limiting febrile illness without recognised cutaneous lesions. None underwent laboratory testing during pregnancy and were retrospectively classified as probable maternal mpox according to the Nigeria Centre for Disease Control and Prevention (NCDC) case definition following laboratory confirmation of MPXV infection in their newborns. All three male neonates presented within the first three weeks of life with fever and disseminated vesiculopustular eruptions. MPXV infection was confirmed by real-time polymerase chain reaction (PCR), and varicella-zoster virus infection was excluded where tested. Two neonates had low cycle threshold values, consistent with a high viral DNA burden. All infants received supportive care. Two recovered completely, whereas one died following early hospital discharge due to financial constraints. All mothers recovered without major complications. Although the temporal relationship between parental illness and neonatal disease suggested epidemiological linkage within the household, the precise route of neonatal acquisition could not be determined because transplacental, intrapartum, and early postnatal transmission remained plausible. Conclusions This multicentre case series expands the limited evidence on maternal and neonatal mpox in a clade IIb endemic African setting and highlights the diagnostic challenges of recognising mpox during pregnancy. Our findings demonstrate a spectrum of neonatal outcomes and underscore the uncertainty surrounding neonatal acquisition. Prospective studies that incorporate comprehensive maternal, neonatal, placental, and household investigations together with viral genomic sequencing are needed to clarify transmission pathways and inform evidence-based strategies for the diagnosis, management, and prevention of mpox during pregnancy and the neonatal period.