We used a single umbilical artery ligation model to induce growth restriction in mid lamb gestation, and then delivered lambs prematurely and ventilated them for a period of 24 hours. Neonatal ventilation and care induced more brain injury in preterm growth restricted lambs as compared to appropriately grown lambs. This was evident on gross histology, and by using specific markers of brain injury. The main mechanisms by which this injury might have resulted from included break down of the blood brain barrier, neuroinflammation and oxidative stress. Interestingly, carotid blood flow was also reduced in the growth restricted lambs.
The Ritchie Centre
Neurodevelopment and Neuroprotection
Journal and article title
This is the first time, preterm growth restricted lambs have been ventilated ex-utero for 24 hours. The ventilation and neonatal care provided was very similar to what happens to preterm infants in the neonatal intensive care unit. The brain injury seen in the growth restricted lambs was greater than that seen in the ventilated appropriately grown lambs,.
Fetal growth restriction, which is poor growth of the fetus during gestation impacts 3-9% of all pregnancies, and the impact on neonatal and future adverse outcomes is exaggerated in preterm growth restricted infants. The neurological mechanisms of brain injury discovered in this study in this vulnerable infant group provide us with potential targets for neuroprotective therapies. This may lead to improved long term outcomes (brain injury, including cerebral palsy) for these infants.
Neonatal brain injury