Contracting the monkeypox virus (mpox) while pregnant can cause Congenital Mpox Syndrome, placental infection, and stillbirth, according to an article from the scientific journal published by the College of American Pathologists (CAP).
Now known as mpox, this poxvirus is related to the now-eradicated smallpox virus. Mpox was known to infect pregnant persons in Africa, producing a 75% perinatal fatality rate, says the article, published online by Archives of Pathology & Laboratory Medicine.
David A Schwartz MD MS Hyg FCAP, a leading perinatal and infectious disease pathology expert, together with five colleagues, evaluated the pathophysiology of mpox in pregnancy, comparing it with smallpox and other poxviruses. They provide insight about how mpox can infect the fetus and describe details of a stillborn with placental infection, define and illustrate the Congenital Mpox Syndrome, and discuss mechanisms of intrauterine mpox transmission.
Dr Schwartz and colleagues say that mpox has the ability to reach and then cross the placenta to infect the fetus prior to delivery following spread of the virus through the mother’s bloodstream. “The description of a stillborn fetus having placental infection with mpox, characteristic skin lesions, an enlarged liver, increased body fluids, and molecular pathology confirmation of mpox in both maternal and foetal tissues, constitutes the Congenital Mpox Syndrome,” explains Dr Schwartz. “This adds mpox to a list of other viral diseases that can cause placental infection and stillbirth including COVID-19, Zika, Ebola, cytomegalovirus, and others.”
Mpox had essentially been restricted to Central and West Africa. Starting in May 2022, mpox was identified outside of these endemic areas, and rapidly spread globally. Although most mpox infections occurred in men, cases in women have increased, resulting in an intense concern for pregnant individuals acquiring the infection.
As of 15 February, 2023, 30,193 cases of mpox occurred in the United States. The US Centers for Disease Control and Prevention reported on 7 November, 2022, that 23 cases of mpox were associated with pregnancy. In Brazil, 22 pregnant persons with mpox have been reported. Several newborns have developed mpox following delivery, likely representing exposure during, or following delivery.
“With the demonstration of intrauterine and postpartum infections from mpox, we can expect that we will see additional cases of perinatal disease,” states Dr Schwartz. “The current outbreak has demonstrated the need for increased research on this most dangerous of poxviruses to human health. Healthcare providers should be aware that mpox occurring in pregnant persons is uncommon but has the capability to infect the fetus as well as the new born and cause both perinatal morbidity and mortality.”
- Schwartz DA, Ha S, Dashraath P, Baud D, Pittman PR, Waldorf KA. Monkeypox Virus in Pregnancy, the Placenta and Newborn: An Emerging Poxvirus with Similarities to Smallpox and Other Orthopoxvirus Agents Causing Maternal and Fetal Disease [published online ahead of print, 2023 Feb 27]. Arch Pathol Lab Med. 2023;10.5858/arpa.2022-0520-SA. doi.org/10.5858/arpa.2022-0520-sa