primary villus

pri·mar·y vil·lus

the first stage of chorionic villus development, with columns of cytotrophoblastic cells covered by syncytiotrophoblast.
References in periodicals archive ?
Primary villus maldevelopment with evidence of reduced placental villus stem arteries and small, fibrotic, hypovascular terminal villi, have been shown in various pathological studies of the placenta of pregnancies complicated by fetal growth restriction (FGR).