At approximately day 1

Hematopoietic stem cells (HSCs) in liver decrease and hematopoietic activity in liver gradually decreases, only small blood islands are present at birth in the liver. Bone marrow takes over as the primary site of hematopoiesis after birth.

Duration: 7 weeks

Reference

Sadler TW. 2004. Langman’s Medical Embryology. Ninth Edition. Maryland: Lippincott Williams & Wilkins.