Objective: We sought to determine morphologically when the maternal uterine circulation to
the human placenta is established. Study Design: We performed a histologic review of 12
early-pregnancy hysterectomy specimens contained within the Boyd Collection, ranging
from 43 to 130 days' gestation. Results: Before the eighth week of pregnancy, maternal
arterial connections with the intervillous space are restricted to tortuous networks of
intercellular spaces. Only after this period can direct channels be observed. Initially, these …

Maternal arterial connections to the placental intervillous space during the first trimester of
human pregnancy : the Boyd collection revisited | CiNii Research … Maternal arterial
connections to the placental intervillous space during the first trimester of human pregnancy
: the Boyd collection revisited …