Question

How is blastocyst connected to maternal circulation?

Answer 1

Through the lytic activity of the syncytiotrophoblast (Fig. 18 and 19) the maternal capillaries are eroded and anastomose with the trophoblast lacunae, forming the sinusoids. At the end of the pregnancy the lacunae communicate with each other and form a single, connected system that is delimited by the syncytiotrophoblast and is termed the intervillous space.