Second pregnancies reshape the brain in unique, non-repeating ways
A study of 110 women tracked from preconception through postpartum found that a second pregnancy leaves brain changes that are distinct from the first: attention and sensory-processing networks show the biggest shifts, while the default mode network changes are less pronounced. Grey-matter reductions averaged 2.8% in second-time mothers (3.1% for first-time mothers across a larger affected region). Brain changes begin in pregnancy and do not fully revert after birth. The imaging patterns relate to bonding strength and to depression risk, with second pregnancies showing earlier depression signals. These findings could improve screening and treatment for maternal mental health and help explain how repeated pregnancies influence long-term brain aging.