Pericarditis in the newborn is a distinct rarity, especially instances of the disease in which the pericardial cavity is completely obliterated. I have been able to find only 7 cases reported in the literature. Because of the rare occurrence of the condition it was thought of interest to report an additional case, in which a complete history of the mother and an opportunity to carry out a careful microscopic study of the infant's heart were presented.
Kelley,1 in 1939, reported a case of fetal pericarditis occurring in a stillborn Negro girl, the product of twenty-two weeks' gestation. The visceral and the parietal pericardial surfaces were thickened and adherent, and when they were pulled apart there was disclosed between them a sticky, adhesive exudate. Microscopic examination showed that these surfaces were covered with a thick layer of granulation tissue, which was densely infiltrated with cells, mostly polymorphonuclear leukocytes. Between the