Potential sequential progression of fetal growth restriction related to placental insufficiency

Progression through this entire sequence does not always occur before delivery; Doppler abnormalities in some growth-restricted fetuses progress slowly or not at all, or along a different pathway. The sequence is most likely to progress when FGR and Doppler abnormalities are identified in the second trimester and the Doppler indices worsen within the first two weeks of Doppler monitoring. The reason why progressive Doppler changes do not always occur is that FGR is not a homogeneous group and different types of FGR behave differently.