- Design
- Systematic review with individual patient data synthesis of published and unpublished cases
- Population
- 55 pregnancies with Crimean-Congo haemorrhagic fever in endemic regions
- Primary outcome
- Maternal mortality and fetal loss
- Effect
- Maternal mortality 28.8% (15/52); fetal loss 57.4% (31/54); third-trimester ribavirin OR 0.33 (95% CI 0.13 to 0.84)
Investigators pooled patient-level data on 55 pregnancies complicated by Crimean-Congo haemorrhagic fever (CCHF), gathered from published reports, unpublished cases and direct collaboration with centres in endemic regions. It appeared in Emerging Infectious Diseases on 1 October 2026.
Maternal mortality was 28.8% (15 of 52 with known outcome) and fetal loss 57.4% (31 of 54). The two risks ran in opposite directions across pregnancy: fetal loss peaked in the first trimester at 85.7%, while maternal mortality rose with gestation to 31.3% in the third trimester. Among third-trimester cases, ribavirin treatment was associated with lower maternal mortality (odds ratio 0.33, 95% CI 0.13 to 0.84).
This is a case series assembled into a meta-analysis, so it shows what happens to women who reach a reporting centre, not to every infected pregnancy. The ribavirin signal is an association in a few dozen women, open to confounding by who was well enough, or reached care early enough, to be treated. Still, it is the best estimate available of how lethal this infection is in pregnancy.
CCHF is not only a Turkish or Central Asian problem. Cases have been reported in western India, with healthcare worker infections. A febrile pregnant woman with bleeding or low platelets and contact with livestock, ticks or slaughter should prompt the question, early isolation precautions and a call to the infectious diseases team.
- Ask about tick bites, livestock handling, slaughter and travel in any pregnant woman with fever and bleeding or thrombocytopenia.
- Use barrier precautions from the first contact; CCHF spreads to staff through blood and body fluids.
- Involve infectious diseases early and notify public health when CCHF is suspected.
- Counsel that fetal loss is most likely early in pregnancy and maternal risk highest late.
- Discuss ribavirin with infectious diseases case by case; the evidence for it in pregnancy is observational.
Why it matters
It puts a number on a risk that has rested on scattered case reports: close to one maternal death in three.
Don't overread it
The ribavirin association comes from a few dozen reported cases and cannot show that ribavirin saves mothers.
The statistics, in plain English
With only 55 pregnancies, every percentage is fragile: one or two cases either way moves the third-trimester figure by several points. The odds ratio of 0.33 means the odds of death were about a third as high in treated women, and the interval (0.13 to 0.84) stays below 1, but women who received ribavirin may have differed in ways the analysis could not adjust for, such as how early they presented.
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