Question

when and how placenta develop on human female?​

Answer 1

Placenta and Embryo at About 8 Weeks

Placenta and Embryo at About 8 WeeksAt 8 weeks of pregnancy, the placenta and fetus have been developing for 6 weeks. The placenta forms tiny hairlike projections (villi) that extend into the wall of the uterus. Blood vessels from the embryo, which pass through the umbilical cord to the placenta, develop in the villi.