While a woman’s body is awash in hormones and undergoing extreme changes during pregnancy, a man’s physical involvement in the matter pretty much ends as soon as it begins. Once that sperm has been deposited in the proper receptacle, his body will return to doing exactly what it was doing before conception, right?
Not exactly. According to Louann Brizendine, a neuropsychiatrist and author of “The Male Brain,” men experience hormonal and even brain changes during their partner’s pregnancy.
The very first change that happens is in the level of cortisol, the hormone responsible for the “fight or flight” response to stress. A man will experience a cortisol surge about four to six weeks after he first learns that he’s going to be a dad. The levels lessen as the pregnancy progresses, but that initial flood, says Brizendine, is likely intended to “alert him that he’d better get things ready.”
As the baby’s due date nears, a man’s testosterone levels will lower by about a third. With reduced levels of the hormone responsible for aggressiveness and sex drive, the dad-to-be will settle down, quit fighting with the other men and, hopefully, refrain from having sex outside the relationship.
But while some hormonal changes in men during a partner’s pregnancy make sense, others are just weird. For example, as his testosterone levels are falling, his prolactin is increasing. Prolactin is the same hormone that helps mothers make milk. What it’s doing in the guys, Brizendine has no idea.
So, how does a man’s body even know to sync up to his female partner’s? Brizendine suspects that the changes are a reaction to the woman’s pheromones sending a chemical message to the man’s brain. And those pheremones, of course, are activated by the baby growing in the womb.
And speaking of brains, research has found that the sight of a cute little baby lights up the same area of a man’s brain that falling in love does. This parental instinct is reinforced the more he holds and cares for his child. And despite the fact that mom may less attentive to dad after the baby’s birth and that the job of caring for an infant is difficult, by this time he’s emotionally and biologically invested and less likely to bolt when the going gets tough.
Which all points to one simple and amazing fact: From the moment they are conceived, babies are totally running the show.
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