title: Transitory thrombocytopenia in newborn mice after intrauterine hypoxia.
abstract: Pregnant mice were exposed to hypobaric hypoxia (0.7 atmospheres) continuously during days 13 to 20 of pregnancy. In the newborn offspring, the body weights were decreased, and liver weight/body weight ratios were increased compared to nonhypoxic control animals (P < 0.001). After intrauterine hypoxia, the newborn animals were polycythemic, and a postnatal transitory thrombocytopenia lasting 7 days occurred. A rebound thrombocytosis appeared on days  13 to 15 after birth. Bone marrow megacaryocyte concentrations were increased in the hypoxic animals on days 5 to 15 after birth compared to the nonhypoxic controls. These findings may be explained by a competitive mechanism on common stem cells. Increased demand for erythropoiesis during hypoxia may shunt hematopoietic cells in direction of erythropoiesis at expense of thrombopoiesis.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000097:blood; D001724:Birth Weight; D004920:Erythropoiesis; D005260:Female; D005311:Fetal Hypoxia / Q000150:complications*; D051379:Mice; D011247:Pregnancy; D013921:Thrombocytopenia / Q000209:etiology*; D013997:Time Factors