Transplacental Transmission Infections: General Consideration. Bacterial Infections

The pathogenesis of lesions and substantial consequences resulting from viral infections during pregnancy still remain largely uncharacterized, in particular, relatively little is known about the fundamental biology behind the vertical transmission of viruses. Although it has been widely accepted that the placenta acts as a defensive barrier against viral insults, the molecular mechanisms underlying control of placental infection are still poorly understood. Several hypotheses have been proposed to explain how the placenta avoids viral infections under normal conditions based on human and mouse studies, which include but not limited to the physical or anatomical defenses, intrinsic cellular mechanisms, the constitutive release of antimicrobial immunomodulators, and so on [1]. Moreover, great progress has been achieved regarding the transplacental transmission and pathogenesis of TORCH pathogens, especially those advanced insights obtained in animal models [2–4].