Prenatal Sex Differences Drive Early Brain Growth, Cambridge Study Finds

Using nearly 800 prenatal and postnatal brain scans, Cambridge researchers mapped brain growth from mid‑pregnancy to the first month after birth and found sex differences emerge before birth, with male brains showing greater overall growth. White matter drives mid‑pregnancy growth while grey matter dominates late pregnancy and after birth, and subcortical grey matter peaks earlier than cortical regions. The team plans to test whether prenatal sex hormones contribute, with potential relevance to neurodevelopmental conditions such as autism.