New dads’ hormones change, too

If you’re a new father and find yourself feeling different after the birth of your child, it may be more than lack of sleep. One prominent study found that testosterone levels drop in new fathers by up to 34 percent, a shift that can begin even before their babies are born. Levels of estradiol—a form of estrogen—drop, too. These changes suggest that suggest new fathers’ bodies and brains are preparing them for fatherhood and help them bond with their newborn ❤️

What do these changes mean?

Hormone changes:

• In studies, new fathers who experienced these changes were more likely to produce the “feel-good” hormones oxytocin and dopamine when interacting with their newborns. 
• The more oxytocin and dopamine present, the more fathers interacted playfully and lovingly with their babies. 

Brain changes:

• Certain parts of the brain associated with empathy are activated in a new father shortly after the birth of their child. This parallels the changes experienced by their partner.
• Studies have shown increased gray matter in these areas of new fathers’ brains, meaning they have developed a higher capacity for nurturing and being responsive to their babies.

Learn more about the research

Gettler, L. T., McDade, T. W., Feranil, A. B., & Kuzawa, C. W. (2011). Longitudinal evidence that fatherhood decreases testosterone in human males. Proceedings of the National Academy of Sciences, 108(39), 16194-16199.