Trophoblast deportation part I: review of the evidence demonstrating trophoblast shedding and deportation during human pregnancy.

Trophoblast deportation was first described before the turn of the 20th Century by the German Scientist Schmorl and is now considered a normal physiological process during human pregnancy. Increased shedding and deportation of placental trophoblast is well documented in preeclampsia, one of the most common diseases of pregnancy. This review summarises the seminal historical and contemporary publications that have contributed to our knowledge of trophoblast deportation to the maternal lungs, their presence and quantity in the maternal circulation during normal pregnancy and during preeclampsia, and the range of morphologies deported trophoblasts display. Finally, the contentious nature of the deported multinucleated trophoblasts' current nomenclature (syncytial knots vs. sprouts) is considered.