This is an ABC podcast.

During pregnancy and then in childbirth, new moms experience some dramatic hormonal changes.

Oxytocin surges during labor to help with contractions, while estrogen and progesterone drop,

which can contribute to postnatal depression.

But while these changes in women are relatively well studied, there is a growing body of evidence finding that biological changes,

that's shifts in hormones and brain activity, happen in men too.

Testosterone can interfere with things like empathy,

and of course we want to be empathic towards our infant,

so a decrease in testosterone makes a lot of sense.

These changes, alongside the regular challenges of being a new parent,

mean some fathers also experience postnatal depression.

It made me wonder whether there was something that we were doing wrong.

There was still that sort of feeling of guilt.

Having a baby that was screaming.

It can be exacerbated by all the things that go on in the transition to fatherhood

or transition to parenthood, things like changes

in sleep patterns, sleep disturbances, that's pretty normal, but also changes in the psychological

adjustment to a role.

You're listening to All in the Mind.

I'm Sana Khadar.

Today, producer James Bullen on how the transition to fatherhood changes dad's brains.

I think I had an expectation that the birth would go smoothly and it would be a really happy

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