Transitory thrombocytopenia in small-for-dates infants, and in newborn mice exposed to hypobaric hypoxia, cigarette smoke and CO gas inhalation during pregnancy

摘要

In 31 small-for-dates infants platelet-counts were recorded during first 2 weeks after birth. In 23 (74%) platelet-counts fell below 100 × 109/1. Thrombocytopenia was significantly more frequent in small-for-dates infants of smoking mothers than in non-smokers. Mated female mice were exposed to hypobaric hypoxia (0,7 atm), cigarette smoke or CO gas during pregnancy. Smoke and CO caused HbCO levels of 4-10%. Intrauterine growth retardation took place in all three groups. Hypoxia caused increased hematocrits at birth, while decreased hematocrits occurred in all three groups day 11-15 after birth. Platelet-counts were decreased first 7-9 days after birth in all groups, followed by rebound thrombocytosis. Bone marrow megacaryocyte-counts increased more rapidly after birth (day 0-5) in the CO group than in controls, while hypoxia caused a later (day 11-15) appearing increase. Competition on common stem cells for erythropoiesis and thrombopoiesis may explain these findings. We suggest that CO toxixity impairs cell growth and proliferation during fetal life, and that deleterious effects of cigarette smoking on fetuses in part may be caused by CO toxicity.