Perinatal tissue oxygenation and neurodevelopment in preterm and growth restricted infants

Preterm birth and fetal growth restriction present major risk factors for an inadequate oxygen supply of the developing brain and other organs. Doppler ultrasound and near-infrared spectroscopy help assess organ oxygen delivery in the fetus and newborn. Using these techniques, this thesis investigated how placental insufficiency and drug exposure before birth affect oxygenation of the brain, kidneys, and intestines in preterm and growth restricted infants. Additionally, this thesis assessed how fetal ‘brain-sparing’ (redistribution of blood flow to the brain at the expense of other organs as a compensatory response to chronically low oxygen levels in placental insufficiency) and oxygenation of the brain after birth relate to neurodevelopmental outcome.
Our data suggest that fetal brain-sparing and higher cerebral oxygen saturations after birth are related to less behavioral problems and better executive functions. On the other hand, fetal brain-sparing may cause cerebral oxygen levels being too high for preterm babies, which we associated with an increased risk of retinopathy of prematurity, a potentially blinding eye condition, and poorer long-term Performance IQ. Epigenetic changes seem to be involved. Moreover, fetal brain-sparing seems to impair autoregulatory mechanisms, with which the brain protects itself from harmful fluctuations in blood flow and oxygenation after birth. Fetal exposure to drugs with vasodilative properties, appeared to also affect organ oxygen delivery in the newborn. This needs to be taken into account when using these drugs in pregnant women or when investigating new treatments for placental insufficiency.