Hilary Duff struggled to get used to sleepless nights after giving birth to her first child, insisting she was wiped out by fatigue.

The singer/actress gave birth to her first child, a son named Luca, last month (Mar12), and tried to battle through nightly feeds and the daily demands of looking after a newborn.

And despite her family and friends warning her it would be hard to enjoy a full night's sleep, the star admits she was still shocked at how tiring motherhood is.

She tells People, "The first week I was like, 'I'm doing this, I'm good. I can not sleep, I can do this.' I don't know where you get that energyfrom.

"Then it hits you - the fatigue. "So many people were like, 'Take naps when your baby naps. So I tried and it really helped a lot.

"I thought when he was napping that was the time I could do all the things I needed to do.

It's a fine balance". However, she reveals she has got little Luca into a good routine after weeks of sleepless nights. She adds, "He's really a good baby, I promise.

"He sleeps really well and he's on a good schedule. He sleeps a good five and six hours a night, which is just amazing. I am so grateful".