Major Study Shows Mpox During Early Pregnancy Linked to 51% Adverse Outcomes
New research from the Democratic Republic of Congo paints a concerning picture for pregnant women exposed to mpox. A study published in The Lancet last week found over half of infected pregnant women experienced adverse fetal outcomes including a 45% rate of fetal loss.
This is the most comprehensive data we have on mpox pregnancy risks to date. And it’s not reassuring.
The Numbers Are Stark
CIDRAP reports the prospective cohort study followed 89 pregnant women with PCR-confirmed mpox infection between December 2022 and June 2025. Of the 69 women with known outcomes, 51% experienced adverse outcomes.
Breaking down that 45% fetal loss rate: 52% were spontaneous abortions, 13% missed abortions, and 35% stillbirths. First trimester infection carried the highest risk – which tracks with how other viral infections behave during pregnancy.
The Lancet study pooled data from four separate research efforts across DRC regions dealing with both clade 1b circulation and endemic clade 1a areas.
For the Babies Who Survived
Of 38 live births recorded, four infants had congenital mpox lesions. One died within hours of birth. The study documented vertical transmission – meaning the virus passed from mother to baby during pregnancy or delivery.
High viral load, genital lesions, and HIV co-infection all correlated with worse outcomes. These risk factors give clinicians something to watch for but dont make the situation any less complicated.
Research Limitations Worth Noting
The study authors acknowledge the challenging conditions in DRC affected data collection. War-torn regions dont make for easy clinical research. Some outcomes were unknown simply because follow-up wasn’t possible.
But even with those caveats, the signal is clear enough. Mpox poses real risks during pregnancy that deserve attention from public health authorities.
What This Means Going Forward
The researchers call for prioritizing pregnant women in vaccination efforts. Previous pandemic responses showed we dont always get vaccination prioritization right the first time.
Current mpox vaccines are available but distribution remains uneven globally. DRC is dealing with ongoing transmission while wealthier countries have largely moved on from the 2022-2023 outbreaks.
For pregnant women in affected areas, the message is straightforward: avoid exposure where possible and seek medical care promptly if symptoms develop. Early intervention might improve outcomes even if we cant prevent all adverse effects.
This wont be the last study on mpox and pregnancy. But its the clearest warning we have right now.
