Placenta is initiated first, as cells of a fertilized egg divide and specialize

The first stages of placental development take place days before the embryo starts to form in human pregnancies. The finding highlights the importance of healthy placental development in pregnancy, and could lead to future improvements in fertility treatments such as IVF, and a better understanding of placental-related diseases in pregnancy.

from Top Health News -- ScienceDaily https://ift.tt/307vSIO