Adaptive changes in the splenic artery and left portal vein in fetal growth restriction

The purpose of this study was to determine whether a low splenic artery pulsatility index (PI) and reduced flow through the left portal vein are involved in redistribution of fetal growth restriction.

Forty-two women with prenatally diagnosed intrauterine growth restriction of singleton fetuses were included. The next pregnant woman with an appropriately growing fetus, matched for gestational age, was selected as a control. Blood flow velocities were measured in the splenic artery and left portal vein. Obstetric and perinatal information was obtained from standardized medical records.

The blood flow through the left portal vein was significantly reduced compared with the controls (P < .0001). Placental impairment in fetal growth restriction was clearly linked to a decreased splenic artery PI (P = .0004). In growth-restricted fetuses with reduced left portal vein flow and a splenic artery PI below the 5th percentile, perinatal mortality, a low 5-minute Apgar score, and neonatal metabolic acidosis were observed significantly more often (P = .04, .01, and .004; P = .03, .03, and .006, respectively).

Reduced blood flow through the left portal vein and low resistance in the splenic artery can be found in growth-restricted fetuses with adverse neonatal outcomes.