Current findings continue to support the concept of a biologically defective decidua rather than a primarily abnormally invasive trophoblast. Prior cesarean sections increase the risk of placenta previa and both adherent and invasive placenta accreta, suggesting that the endometrial/decidual defect following the iatrogenic creation of a uterine myometrium scar has an adverse effect on early implantation. Preferential attachment of the blastocyst to scar tissue facilitates abnormally deep invasion of trophoblastic cells and interactions with the radial and arcuate arteries. Subsequent high velocity maternal arterial inflow into the placenta creates large lacunae, destroying the normal cotyledonary arrangement of the villi.
*UCL Institute for Women’s Health, University College London (UCL), London, UK
†Department of Physiology, Development and Neuroscience, The Centre for Trophoblast Research, University of Cambridge, Cambridge, UK
The authors declare that they have nothing to disclose.
Correspondence: Eric Jauniaux, MD, PhD, FRCOG, Academic Department of Obstetrics and Gynaecology, Institute for Women’s Health, University College London, 86-96 Chenies Mews, London, UK. E-mail: email@example.com