Influenza infections during pregnancy: association with congenital malformations and with subsequent neoplasms in children, and potential hazards of live virus vaccines

Abstract

No direct association exists between maternal influenza infections and either congenital malformations or subsequent neoplasms during childhood. No investigation, however, has been made in sufficient depth to verify this conclusion, and a large prospective study is urgently needed to provide a proper assessment of the putative hazards. This could best be undertaken in an area with a relatively stable population and with recognized pediatric and maternity hospital facilities. It is interesting to note that, despite widespread use of live influenza vaccines in Yugoslavia, no increase in the incidence of congenital malformations or subsequent childhood malignancies has been observed. The widespread use of live influenza vaccines should present little risk to the fetus in terms of congenital malformations or subsequent childhood leukemia, either by transmission from vaccinated individuals or by accidental vaccination in women whose pregnancy has not been detected. Nevertheless, precautions similar to those employed in rubella vaccination would be advisable until more information becomes available.