Early loss of human chorionic gonadotropin in preterm infants: Implications for brain and eye development

Human chorionic gonadotropin (hCG) is a placental hormone that is essential to maintaining pregnancy. However, evidence suggests that its influence extends to the central nervous system. Receptors for hCG are present on neurons, glial cells, and neural precursor populations, raising the possibility that hCG supports retinal and brain development. This possibility has important implications for preterm infants, whose hCG levels drop abruptly after early separation from the placenta rather than declining gradually in utero. In this article, I review the locations of hCG receptors in the developing brain of humans and summarize evidence linking hCG to angiogenesis (blood vessel formation) and neuroprotection. I propose that early loss of hCG in preterm infants may increase their vulnerability to cerebral palsy, retinopathy of prematurity, and other neurodevelopmental disorders.