For many of us, when it comes to having baby number 2 we're a bit more relaxed.
We've done it before, after all, and know what to expect a bit more than we did with our first.
So, when things aren't quite the same as they were first time around - perhaps baby no 1 was a great sleeper and baby no 2 turned out not to be - it can come as a bit of a shock.
That was the scenario for The Saturdays singer Una Healy, who has spoken to the Press Association about how she experienced postnatal depression when her youngest son Tadgh was born - despite being fine with her first child, daughter Aoife.
"When I had Tadgh, I had a touch of PND, something I didn't experience when Aoife was born," she says.
"It was a lonely time and I wasn't helping the situation. I was moving to a new house, Ben had suffered an injury at work and I also jumped back into work quicker than I did when I had Aoife.
"I thought I would be fine, and could do it all because I'd had a child before.
"[I] started to feel alone and withdrawn. All this added up, and finally I went to my GP who diagnosed postnatal depression. I was offered medication but having tried both, preferred the cognitive therapy route.
"Talking, whether to my GP or to friends and other new mums, was so helpful for me."
Luckily, Una sought the help she needed, and got it. She learnt to open up to others about what she was going through - something vitally important which not all mums feel able to do, which can have heartbreaking consequences.
We're grateful Una has shared her story, and hope it will encourage other mums to speak up if they're going through a tough time ?
Image: Una Healy on Instagram