What Role Do Hormones Play in Fatherhood?

When my sister told me she'd learned that a man's testosterone levels typically lower when his wife is pregnant, or has just had a baby, we chuckled a little and spent some time speculating why that might be. Since testosterone is often associated with aggression, we thought it might be an inbuilt infant-protection mechanism. Nature's way of getting a man to slow down and direct a more tender and gentle attitude towards wife and new baby.

As I discovered, this is actually fairly close to the truth. USA Today reports that recent studies have demonstrated that testosterone levels in a man fall off quite dramatically a few weeks before his baby is born, while prolactin levels rise by a similar percent, until things adjust back to normal when the baby is about 6 weeks old.¹ The article goes on to discuss changes to male brain chemistry that may account for these hormonal changes. Nobody is quite sure in which direction this process works or precisely what triggers them, but it is possible that the baby in the womb may play a part in these changes, through it's own hormonal influence on the mother, who then has some hormonal influence on the father.

Being married to a man who is definitely not the nurturing type in general, and having three young sons who show signs of having more than enough testosterone, in hindsight I can see how this research makes sense. My husband was a different man during those few weeks before, and the few weeks after birth--thoughtful, concerned for my health and the baby, tender and gentle, emotionally invested. All these things are not typical to his personality at all, and it was somewhat disconcerting to see such a huge change in him. I'm sure he found it more than a little perturbing as well. The research says nothing about hormonal changes in young males, but I have seen parallels in my little boys' behavior as well. Normally, they'll turn any found object into a weapon. When we're baking, they speak about it in aggressive terms ("Look, the milk and oil are separated! They're fighting! The oil is winning!" or "I love beating bread dough!"). However, put a newborn sibling or cousin in their arms, and they melt into puddles of gentle adoration, and start proclaiming their desire to grow up and be daddies who change diapers and make their babies laugh.

We can easily see the upside of these changes. Who doesn't admire a man who waits hand and foot on his pregnant wife and is deeply committed to her health and comfort? Who isn't moved when a man who is the toughest of the tough finds that even he is vulnerable to overwhelming emotions and tears as his wife labors and delivers their baby? Who doesn't want to see a father doting on his baby sweetly? But some responses to this news reveal that people do worry about a man becoming "feminized" if he nurtures his infant. This is not the case. As was mentioned previously, hormonal levels return to normal at about 6 weeks after the baby's birth. Furthermore, since this hormonal response is built into a man's system, it is not "unmasculine" to participate in the nurturing of his child. Regardless of how one feels about gender roles, it is clearly in the best interests of the family--and possibly society³--when a baby has two parents who are deeply invested in meeting his or her needs, most particularly in those early weeks when sleep deprivation and stress are at their highest.

These hormonal changes in men are just beginning to be understood, but their effect makes perfect sense in the context of the health, happiness, and preservation of the human species.

¹Dad's hormones change too, during pregnancy, Liz Szabo, USA Today
²New dad: Tips to help manage stress, staff, Mayo Clinic
³The Nurturing Father, James Kimmel Ph.D., The Natural Child Project