Placental insufficiency and fetal growth restriction.

OBJECTIVES: Fetal growth restriction is defined as a pathologic decrease in the rate of fetal growth. The most frequent etiology for late onset fetal growth restriction is uteroplacental dysfunction which is due to inadequate supply of nutrients and oxygen to support normal aerobic growth of the fetus. However, for symmetrical IUGR, fetal chromosomal anomalies, structural anomalies and fetal infections should be carefully excluded. Consequent to the uteroplacental vascular maladaptation of endovascular trophoblastic invasion, there is increased vascular resistance and decreased blood flow to the placenta in the choriodecidual compartment.
CONCLUSIONS: This under perfusion of the placenta causes villous damage; that is, total tertiary villous capillary bed is reduced leading to increased placental resistance. These changes can be diagnosed by Doppler and characteristic changes are seen in the uterine, umbilical, middle cerebral arteries and ductus venosus vessels. In severe cases, delivery of the fetus with optimum intrapartum surveillance, or caesarean section, is essential.