The document describes fetal growth and development from fertilization through the three trimesters. It discusses the formation and functions of the placenta, amniotic sac, umbilical cord, and other structures that support the growing fetus. Key events include implantation of the blastocyst 8-10 days after fertilization, formation of the placenta and amniotic sac, and the establishment of maternal-fetal circulation through the placenta by 12 days of gestation. The umbilical cord develops to connect the fetus to the placenta and transport nutrients and waste.