Placental Insufficiency

Excerpt

Placental insufficiency, also known as uteroplacental insufficiency, contributes to a broad spectrum of obstetric complications, including preeclampsia, fetal growth restriction (FGR), oligohydramnios, and stillbirth. This condition accounts for a substantial proportion of global perinatal morbidity and mortality. Despite extensive research, no universally accepted definition has been established. The disorder generally involves inadequate placental perfusion, which leads to insufficient delivery of oxygen and nutrients to the fetus.

Recent evidence underscores the lack of a pathognomonic clinical or histologic marker, creating challenges in achieving uniform diagnosis and study of placental insufficiency. Current understanding characterizes the condition as a progressive decline in placental function that culminates in chronic fetal hypoxemia, metabolic acidosis, and FGR. Please see StatPearls' companion resource, "Fetal Growth Restriction," for further information. Physiologically, hypoxemia triggers adaptive fetal responses, including redistribution of blood flow toward vital organs (brain sparing), diminished fetal movement, and reduced somatic growth. Histopathologic patterns commonly linked to placental insufficiency include distal villous hypoplasia, increased syncytial knots, maternal vascular malperfusion, placental infarctions, and fibrin deposition.

Advanced imaging modalities, including placental magnetic resonance imaging (MRI) and 3-dimensional power Doppler, have demonstrated potential in quantifying abnormal placental morphology and perfusion. These technologies reveal findings, eg, reduced placental volume and altered vascular resistance. Although not yet standard in clinical practice, such imaging may enable earlier detection of high-risk pregnancies in the future.