Q fever during pregnancy: a narrative review

Coxiella burnetii, the causative agent of Q fever, causes abortions in animals. Its effects on pregnancy in humans and the management of Q fever in pregnancy are uncertain.

To summarize data on the effects of Q fever on pregnancy in women, the effects of pregnancy on Q fever complications and the optimal screening and management of Q fever during pregnancy.

We searched for studies reporting on Q fever during pregnancy in women. We included randomized and observational studies, seroprevalence studies, case series and case reports, including clinical and histopathological studies.

The accumulating data seems convincing that Q fever increases the risk of abortions in early pregnancy and prematurity or intrauterine fetal demise in late pregnancy. Data are based on sero-epidemiological associations of Q fever and adverse pregnancy outcomes and case reports showing the presence and effects of C. burnetii on the placenta and the fetus. Based on observational studies, acquisition of Q fever during pregnancy also increases the risk for maternal chronic Q fever. Treatment of recently infected women seems to improve these outcomes, based on case series only, but the optimal duration of treatment has not been studied. The efficacy of active surveillance during pregnancy, timing and frequency have not been determined in high-endemicity settings. Obstetricians should be aware of the risk for transmission of the disease during delivery. Currently available data are based mostly on case series and case reports, with some discrepancy between the French experience in chronic endemicity settings and Dutch experience in outbreak settings.

Since infection with Q fever is largely asymptomatic, we believe that the accumulating information linking Q fever to adverse pregnancy outcomes justifies screening in the high-endemicity setting and treatment of infected women. High-quality research addressing the questions raised by this review is needed to determine the optimal public health policy.