Father’s Day is a holiday of honoring fatherhood and paternal bonds, as well as the influence of fathers in society. Less well known is the influence of parenthood on fathers, and their brains. A study¹ published in Cerebral Cortex last year by Magdalena Martínez-García et. al. offers some the details.

The study is part of Magdalena’s Ph.D Thesis on Characterization of gestational brain remodeling in human mothers:

During the nine months of human pregnancy, a woman’s body undergoes extreme changes to gestate, accommodate, deliver, and nourish her baby: her blood volume almost doubles, her mammary glands begin to produce milk and a new organ appears, the placenta, which will secrete enormous amounts of hormones that will coordinate all these adaptations. Another system in a mother’s body undergoes major adaptations during pregnancy: her brain. The nature of this brain remodeling is still in its early years of research.

The present thesis constitutes the first approach in literature to characterize previously observed changes in brain volume in mothers

And also fathers!

There is a small but consistent decrease in the volume of the cortices of new fathers after the birth of their child. Cortical volume reductions do not depend on the fathers’ age at the prenatal scan or their child’s age at the post natal scan. They mostly affect cortical circuits, involved in social understanding, and not subcortical circuits associated with reward processing and motivational approach.

Emerging evidence points to the transition to parenthood as a critical window for adult neural plasticity. Studying fathers offers a unique opportunity to explore how parenting experience can shape the human brain when pregnancy is not directly experienced. Yet very few studies have examined the neuroanatomic adaptations of men transitioning into fatherhood. The present study reports on an international collaboration between two laboratories, one in Spain and the other in California (United States), that have prospectively collected structural neuroimaging data in 20 expectant fathers before and after the birth of their first child. The Spanish sample also included a control group of 17 childless men. We tested whether the transition into fatherhood entailed anatomical changes in brain cortical volume, thickness, and area, and subcortical volumes. We found overlapping trends of cortical volume reductions within the default mode network and visual networks and preservation of subcortical structures across both samples of first-time fathers, which persisted after controlling for fathers’ and children’s age at the postnatal scan. This study provides convergent evidence for cortical structural changes in fathers, supporting the possibility that the transition to fatherhood may represent a meaningful window of experience-induced structural neuroplasticity in males.

There ain’t no such thing as a free lunch, particularly in nature.

Enjoy your children!

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(1) Magdalena Martínez-García, María Paternina-Die, Sofia I Cardenas, Oscar Vilarroya, Manuel Desco, Susanna Carmona, Darby E Saxbe, First-time fathers show longitudinal gray matter cortical volume reductions: evidence from two international samples, Cerebral Cortex, 2022;, bhac333, https://doi.org/10.1093/cercor/bhac333

Featured Image: Dads Adventure. (Illustration do not reflect the actual regions of your brains)