Beyond the expected, like morning sickness and weird food cravings, pregnancy can cause all sorts of bizarre changes in the body. Research has shown that these changes extend even as far as the structure of the brain, which makes sense when you consider that the body is growing an entirely new life and preparing for the years of parenting ahead. But it takes two to tango – so can being around a pregnant mother cause changes in the father’s brain too?
According to psychiatrists Dr Hugo Bottemanne and Dr Lucie Joly, who discussed this topic in a recent viewpoint article in the journal JAMA Psychiatry, the answer is very much yes, and it’s attracting more and more attention from scientists. “A growing number of human brain imaging studies have focused on changes in the paternal brain after childbirth,” the pair write.
While it may seem counterintuitive that something happening in another person’s body can have such profound effects on someone else, for experts in this field it’s very logical.
“Mum and dad are as biologically primed to parent as each other. That’s the big new understanding about parenthood – in the past we thought only women underwent bodily changes, mainly as a product of pregnancy and childbirth, but actually men go through similar things too,” evolutionary anthropologist Dr Anna Machin told the BBC.
While some of the research in this area has concentrated on hormonal changes, Machin explained that brain changes are the other big focus.
What changes happen in the paternal brain?
According to Bottemanne and Joly, brain imaging studies have shown that fathers can experience alterations in gray matter across many different brain regions. Gray matter is the cortical tissue that forms the outer surface of the brain, as well as pockets deeper inside, and consists mainly of the cell bodies of neurons.
One 2014 study they cite included 16 fathers, seven of whom had become parents for the first time. They underwent MRI scans when their babies were 2-4 weeks and 12-16 weeks old, as well as a standardized test for depression, and the researchers also filmed and analyzed short interactions between the fathers and their kids.
The scans demonstrated increased gray matter in regions associated with parental motivation, including the hypothalamus, amygdala, and lateral prefrontal cortex. Decreased gray matter volume was observed in the orbitofrontal cortex, posterior cingulate cortex, and insula.
“The findings may shed light on the brain regions that adopt structural changes in concert with the human father’s transition to parenthood and regulate each father’s ability to develop appropriate parental behaviors and regulate postpartum mood,” the authors concluded.
Bottemanne and Joly go on to detail other research, suggesting that functional changes have been observed in fathers compared to non-fathers when exposed to stimuli like videos or audio recordings of their kids. The brains of the data show greater activation in various regions compared with the non-fathers in these scenarios, but it’s not clear whether this starts to appear postpartum or during pregnancy.
Bringing things right up to date, a 2023 study compared two cohorts of fathers: 20 in Spain and 20 in California. They were compared with a control group of 17 men in Spain with no children. MRI scans revealed a number of brain changes in both cohorts of fathers as they were monitored during their partner’s pregnancy and just after the birth. The brain regions involved were areas that contribute towards attention, empathy, and visual processing – so all things that are associated with parenting. These changes were not observed in the child-free control group.
The role of neuroplasticity
The fact the brain can undergo such shifts at all is thanks to the phenomenon of neuroplasticity, which allows our brains to adapt and change even into adulthood. It’s the same thing that allows the brain to compensate for the loss of one of the senses, for instance.
Parenting researchers have suggested that rather than paternal/maternal “instincts” being truly instinctual, they come about as a result of a parent spending time with their child and the brain adapting as a result.
“Fathers are made, not born,” wrote Dr Darby Saxbe (one of the authors of the 2023 study) and then-doctoral student Sofia Cardenas in a 2021 opinion piece for the New York Times. They pointed to the importance of governments offering paternity leave, to allow fathers this crucial bonding time with their kids as well as improving mental health for both parents.
Ultimately, Bottemanne and Joly conclude, there’s still a lot left to uncover in this area. We can say with some certainty that pregnancy has the potential to cause substantial changes in the brains of both mothers and fathers, but we still need more research to tease out exactly what that looks like.
“As with the maternal brain, longitudinal studies are needed to compare morphologic and functional changes in fathers’ brains during preconception, pregnancy, and the postpartum period,” they write. “We urgently need to better understand the cerebral processes that affect the paternal brain.”
