Hormones play a vital role during pregnancy that leads to various changes in your body and also hamper your mood. Men do undergo the same changes as that of women too. Just because they do not carry the baby or breastfeed them does not mean that they do not have such bodily changes.

Previous studies have indicated that man’s hormonal levels changes after becoming a father. However, new studies point out otherwise. “Our findings suggest that these changes may begin even earlier, during the transition to fatherhood,” said lead study author Robin Edelstein from University of Michigan.

During the study, researchers found that women showed large prenatal increases in salivary testosterone, cortisol, which is primarily know as the stress hormone, estradiol that functions like estrogen and progesterone. On the other hand men showed significant prenatal declines in testosterone and estradiol but no detectable changes in cortisol or progesterone. While the results in women were expected, the results seen in men suggest that impending fatherhood might cause men’s hormone levels to change. Lower testosterone level in men reduces aggression and helps to bond better with the baby after the birth.

“We do not yet know exactly why men’s hormones are changing, these changes could be a function of psychological changes that men experience as they prepare to become fathers, changes in their romantic relationships, or even physical changes that men experience along with their pregnant partners,” Edelstein explained.

Additional studies are warranted to understand whether partners prenatal hormone changes are linked with postpartum behavior and adjustment.