Even Men Go Through Hormonal Changes During Partner's Pregnancy

A lot of studies on pregnancy and parenthood are divided on gender lines. What happens to the body is restricted to women during the expectant months; what happens afterwards is spread between both parents. If you're a man and your partner's pregnant, chances are you're also going to experience some interesting changes in your hormonal make-up, though as yet we're not entirely clear what some of them are, or why.

# It's well known that testosterone levels in new dads plunge after birth, but it's recently been noted that the process of lowering testosterone starts before the baby's even born, in the last trimester of the pregnancy. The levels of testosterone in a man's blood seem to dip by up to a third in the three weeks before the baby's due date, as the world of fatherhood is really looming.

# When it comes to milk production, it seems that the actual pregnant woman doesn't have the monopoly on it. Prolactin, the hormone secreted by the pituitary gland to stimulate milk production, is found in whopping amounts in expectant mothers, but it also spikes in expectant dads, reaching its highest levels after the baby's been born.

# A study published in Evolution And Human Behavior showed that fathers-to-be have higher levels of the stress hormone cortisol in the three weeks before the birth than they do in the rest of it, around double the amount, in fact.

# Estradiol is a variant on oestrogen, and the same 2014 study that found no particular change in cortisol levels also found that estradiol levels dropped off too. While the study group of the experiment, done by the University of Michigan, was very small, it's a strange discovery, because on the face of it, it doesn't seem to make sense.