Pathophysiology
If the cause of IUGR is extrinsic to the fetus (maternal or uteroplacental), transfer of oxygen and nutrients to the fetus is decreased. This causes a reduction in the fetus’ stores of glycogen and lipids. This often leads to hypoglycemia at birth. Polycythemia can occur secondary to increased erythropoietin production caused by the chronic hypoxemia. Hypothermia, thrombocytopenia, leukopenia, hypocalcemia, and pulmonary hemorrhage are often results of IUGR.
If the cause of IUGR is intrinsic to the fetus, growth is restricted due to genetic factors or as a sequela of infection.
Read more about this topic: Intrauterine Growth Restriction