Infectious Diseases

Abstract

Prenatal infections are common and varied. Their pathogenesis and related circumstances must be understood if the pathological lesions are to be interpreted correctly, and although many types of infection cause placental changes, in some types, the infection may be difficult to prove from placental examination alone. Infections may ascend from the endocervical canal, or they may reach the placenta hematogenously through the maternal blood. Rarely are they iatrogenic and acquired by amniocentesis, chorionic villus sampling, amnioscopy, percutaneous umbilical blood sampling (PUBS), or intrauterine fetal transfusion. Rare cases may also develop from direct infection from the endometrium. Many infections cause gross and microscopic changes of the placenta, but others, e.g., most cases of Coxsackie virus infection, leave few characteristic or specifically recognizable traces. This is also the case with parvovirus B19 infection, which often leads to fetal hydrops but has no specific placental alteration other than the classic intranuclear inclusions in nucleated red blood cell precursors and endothelium (Hartwick et al. Teratology 39:295–302, 1989). Rarely both Coxsackie and parvovirus B19 (Samra et al. Obstet Gynecol 73:832–4, 1989) do result in lesions (see discussions below).

This chapter first covers a general discussion of chorioamnionitis, followed by infections with specific organisms, both common and rare. A complete review of the early literature, especially the European references, may be found in the work of Flamm (Die pränatalen Infektionen des Menschen. Unter besonderer Berücksichtigung von Pathogenese und Immunologie. Stuttgart: Georg Thieme; 1959). Reviews of fetal and placental infections have been provided by Blanc (Pathology of the placenta, membranes, and umbilical cord in bacterial, fungal, and viral infections in man. In: Naeye RL, Kissane JM, Kaufman N, editors. Perinatal diseases. Baltimore: Williams & Wilkins; 1981. p. 67–132), Altshuler (Altshuler G. Placental infection, and inflammation. In: Perrin EVDK, editor. Pathology of the placenta. New York: Churchill Livingstone; 1984. p. 141–63; Role of the placenta in perinatal pathology (revisited). Pediatr Pathol Lab Med. 1996;16:207–33), and Carroll et al. (Preterm prelabour amniorrhexis. New York: The Parthenon Publishing Group; 1996). A comprehensive text on infections of the fetus and newborn infant by Wilson et al. (2015) can also be consulted. Additional references are included in the specific discussions. An excellent overview of the role of the placenta in the defense against infections, and the manifestations of a wide variety of infections, has recently been provided (Heerema-McKenney, APMIS 126:570–88, 2018). Hematogenous infections are reviewed by Bittencourt and Garcia [9].