A new study found that expectant fathers are experiencing changes in their hormones as their wives proceed with the pregnancy. The researchers identified two hormones -- testosterone and estradiol -- that drop prior to their babies' birth.
Robin Edelstein of the University of Michigan and his colleagues involved 29 expectant heterosexual couples who are about to be parents of their first-born. The couples underwent a series of tests evaluating their hormones -- salivary testosterone, cortisol, estradiol and progesterone -- during the 12th, 20th, 28th and 36th weeks of pregnancy.
The analysis showed that all four hormones surged for the pregnant women while the expectant fathers' testosterone and estradiol plunged. The researchers admitted that further research is needed as they couldn't tell the cause of the hormonal changes in men. They presumed that the expectant fathers could be psychologically preparing themselves to be a father and provide care to their children.
"We don't yet know exactly why men's hormones are changing," Edelstein said in a university news release. "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.
"Nevertheless, fathers' hormonal changes could have important implications for paternal behavior once their babies are born."
Dr. Tomer Singer, a reproductive endocrinologist at Lenox Hill Hospital in New York City, found the findings of the study interesting but saw some limitations. He pointed out the small sample size, the ethnicity of the participants who were mostly white, their high education level and high income.
"They would probably have to repeat this in a larger group before coming to any conclusions," he told HealthDay News. Singer was not part of the study.
This study was published in the Dec. 15 issue of the American Journal of Human Biology.
