Second Pregnancy Reshapes the Brain in Distinct Ways

A study published in Nature Communications by researchers at Amsterdam UMC reveals that a second pregnancy changes the brain in both similar and distinct ways compared to a first pregnancy. Building on previous work showing that pregnancy reshapes the brain, the researchers followed 110 women, including first-time mothers, second-time mothers, and childless women, using repeated brain scans.

“We have shown for the first time that the brain not only changes during the first pregnancy, but also during a second,” said Elseline Hoekzema, head of the Pregnancy Brain Lab at Amsterdam UMC. “Each pregnancy leaves a unique mark on the female brain.”

The study found that a first pregnancy produces the largest changes in the brain’s Default Mode Network, involved in self-reflection and social thinking. During a second pregnancy, this network changes again but to a lesser extent. Instead, the most noticeable changes occur in networks responsible for attention and sensory processing. “It appears that during a second pregnancy, the brain is more strongly altered in networks involved in reacting to sensory cues and in controlling your attention,” explained researcher Milou Straathof. “These processes may be beneficial when caring for multiple children.”

The research also uncovered links between pregnancy-related brain changes and maternal bonding, with a stronger connection after the first pregnancy than the second. Additionally, for the first time, changes in the brain’s cortex were associated with peripartum depression. The timing of these associations differed: for first-time mothers, they were more apparent after childbirth, while for second-time mothers, they were more noticeable during pregnancy. The authors emphasize that this knowledge can help understand and address mental health issues in mothers.