How the Brain Fine-Tunes Itself in Preparation for Childbirth

Image of brain changes related to pregnancy generated by OpenAI’s ChatGPT.

Pregnancy is a transformative period where women’s bodies and brains change rapidly to support the growth of a fetus. Despite these significant changes, scientists have yet to develop a detailed map of how the pregnant brain transforms.

A recently published study in Nature Neuroscience tackled this problem. The researchers scanned a 38-year-old woman’s brain over multiple sessions starting before conception until two years after pregnancy. They measured changes in brain structure to identify brain regions prioritized by the demands of impending parenthood.

The study found that several brain regions involved in sensory processing and attention decreased in volume, while connections between regions involved in emotional and visual processing were strengthened. These changes were linked to increases in sex hormone levels -- particularly estradiol and progesterone -- characteristic of pregnancy. 

At first, these results may seem like pregnant women are “losing” brain cells. However, a more reasonable theory is that changes to sex hormone levels “fine-tune” the brain, preparing it for parenthood by enhancing the ability to respond to visual and auditory infant cues.  

This research is transformative for women’s health and neuroscience by providing valuable insights into how brain health outcomes are related to pregnancy.

Original Article: Pritschet, L., Taylor, C.M., Cossio, D. et al. Neuroanatomical changes observed over the course of a human pregnancy. Nat Neurosci 27, 2253–2260 (2024). https://doi.org/10.1038/s41593-024-01741-0