Spiral Artery Transformation and Trophoblast Invasion in Early and Late Miscarriage

Extravillous trophoblast (TB) invasion of uterine decidua and myometrium and the associated spiral artery (SA) ‘transformation’ are essential for the development of normal pregnancy. Small pilot studies have suggested that impaired interstitial and endovascular TB invasion may play a role in the pathogenesis of miscarriage (MC). The hypothesis that MC is associated with reduced extravillous TB invasion and SA transformation was tested in a large series of placental bed biopsies containing decidua and myometrium and at least one SA artery from karyotyped embryonic MCs (13 weeks’ gestation n=26) dated by last mens…