The Effect of Asian Influenza on the Outcome of Pregnancy, Baltimore, 1957-1958

Abstract

Six hundred seventy-one women were studied prospectively by epidemiologic and serologic means during the fall and winter of 1957 -58 to determine the effect of infection with influenza virus type A2 (Asian) upon the outcome of pregnancy. Clinical data and serums were collected at monthly intervals during prenatal care and at delivery. Serologic confirmation was obtained in 94% of the women who claimed illness. Inapparent (serologically determined) infection occurred in 75% of the women denying "flu-like" illness. Influenzal infection (even if clinically inapparent) appeared to have an adverse effect on the outcome of pregnancy especially if the infection occurred during the first trimester. Further study is indicated to determine whether this trend is significant and therefore real.