*4.1. Placental Tissue Collection*

Placental tissues from patients delivering by cesarean section at full term (mean gestational age: 39 ± 1 weeks of gestation) were obtained from Antoine Béclère Hospital (Clamart, France), Antony Hospital (Antony, France), Port-Royal Maternity (Paris, France) and Montsouris Mutual Institute (Paris, France). Indications for cesarean sections were: maternal uterus abnormalities (uterus scar, myomectomy), maternal wish, breech presentation, narrow maternal pelvis. Placentas were collected following informed patient written consent and approval from our local ethics committee (CPP 2015-mai-13909). All the collected placentas resulted from monofetal non-complicated pregnancies, i.e., with no fetal abnormalities, no maternal diseases or treatment (i.e., diabetes, thyroid disorder, hypertension, pre-eclampsia). Placentas included were all macroscopically normal (weight and macroscopic examination).
