Fathers-to-Be Go Through Hormonal Changes, Too
June 23, 2000 -- We've all heard about the hormonal changes women go through during and after pregnancy that help them get ready for motherhood, but some researchers are uncovering evidence that points to parallel hormonal changes in fathers-to-be. The researchers theorize that these changes may help make these men kinder and gentler ? in other words, more paternal.
Hints of what these powerful hormones are capable of have already been detected in animals. Consider the male Siberian dwarf hamster. "He is such an extraordinary dad that he midwives the delivery of his babies. He actually pulls them out of the birth canal and opens their airway, cleans off their membranes, and enjoys sharing the placenta with mom," evolutionary endocrinologist Katherine Wynne-Edwards, PhD, tells WebMD.
While you may not see many human males displaying that kind of behavior, Wynne-Edwards, a professor at Queen's University in Kingston, Ontario, believes that hormonal changes in men may help them prepare for fatherhood in more subtle ways.
In her most recent study, she and her colleagues recruited 33 Canadian couples and collected saliva samples from both partners from as early as 10 weeks into the pregnancy through one month after birth. In some cases, the couple even gave samples during the actual delivery. Wynne-Edwards hopes that hormonal changes the researchers found in the saliva may someday be found to be linked to behavioral changes. She presented her findings at the recent annual meeting of the Endocrine Society in Toronto.
"We were interested in conducting the study because we know that in animals, hormones influence maternal behavior," says Wynne-Edwards, noting that research has also found hormonal influences on fatherly behavior in male animals.
She says that what the researchers wanted to do first was test the hypothesis that the fathers' hormones would change during their partners' pregnancies. "And secondly, we have an expectation that if hormones change in men, that they'll be a muted version of [what] females are using to turn on maternal behavior," she says.
When Wynne-Edwards compared the hormone levels of the fathers-to-be with a group of nonfathers, she found that the expectant dads had higher levels of estradiol (a female hormone), lower testosterone levels, and lower levels of the stress hormone cortisol. But she also found that both testosterone and cortisol levels were elevated just before the birth and suppressed immediately afterwards.