Monochorionic twin pregnancies carry a risk of perinatal complications due to shared placental anastomoses, which can cause uneven blood distribution and lead to conditions like selective fetal growth restriction (sFGR). This case describes a monochorionic pregnancy complicated by preeclampsia and late-onset sFGR of twin B. Labor was prematurely induced and a 45% weight discordance between the twins was confirmed. Twin A adapted well to extrauterine life, but a routine cerebral ultrasound on the second day revealed a periventricular venous infarction. Subsequent brain magnetic resonance imaging (MRI) confirmed deep medullary vein thrombosis and multiple small ischemic lesions secondary to hypoxia. Twin B, born with anhydramnios, experienced several perinatal complications including resuscitation at birth and acute kidney injury. By the fourth day, twin B developed inconsolable irritability, intermittent opisthotonus, and a cortical thumb. The brain MRI showed pachygyria, suggesting a cortical development malformation. sFGR can lead to severe cerebral injuries and adverse neurodevelopmental outcomes, often impacting the larger twin due to acute in-utero blood volume shifts between the twins through placental anastomoses, while also causing brain growth restriction in the smaller twin. Balancing the risks of prematurity against the potentially serious outcomes in twins poses a significant challenge in the management of sFGR cases.