Placental lactogen is a haemopoietic hormone.

The anaemia and thrombocytopenia of hypophysectomized (Hypox) rats could be corrected readily by daily treatment with human placental lactogen. Spontaneous DNA synthesis in the bone marrow of Hypox rats was grossly impaired, which was also normalized by placental lactogen. Human placental lactogen exerted a direct mitogenic effect on rat bone marrow cells in vitro. These results indicate that placental lactogen is a potent haemopoietic hormone.