Pregnancy and influenza: pathological manifestations of the infection caused by virus A/H1N1

Background. Pregnant women are a high-risk group for severe complications and mortality from influenza. There is limited information on the detection of specific pathological signs of viral injury of the organs outside the respiratory system, as well as of the placenta and fetus by transplacental passage. Purpose. In this paper clinicopathologic peculiarities of lung lesion and associated morphological changes outside the respiratory system have been studied. Materials and methods. The author has analyzed 4 fatal outcomes of influenza A/H1N1 which occurred at hospitals of the Arkhangelsk region in women who become ill on the third trimester of pregnancy in 2009 and 2011. The analyses of patient cards, autopsy data and postmortem histological examination have been performed. The results were compared with clinical and morphological data of influenza A/H1N1 fatal outcomes in 8 non-pregnant adults (control group). Microscopic changes in the placenta and lungs of antenatal deceased fetus have been investigated in one case. Results. The clinical presentation and morphological findings in respiratory system in pregnant women were not different from those of the other patients died from total viral pneumonia. However, morphological signs of generalized influenza infection with brain and heart involvement were observed in three of the four pregnant women, while in the control group outside respiratory specific changes, characteristic for infection caused by the flu virus, were not detected. In one case with identified morphological signs of generalized infection in the mother’s body a similar changes in the placenta and lungs of antenatal deceased fetus were confirmed.

pregnancy, fatal outcomes, autopsy, morphology