Haylie Duff has been "fighting" against wearing maternity clothes throughout her pregnancy.

Haylie Duff

Haylie Duff

The 'Napoleon Dynamite' star - who is the older sister of singer and actress Hilary Duff - admitted she has tried to avoid unsightly styles for expectant mothers but has finally had to give up and don the stretchy garments as she has entered her third trimester and her baby bump is getting too big.

She said: "I was fighting the good fight on buying maternity clothes, but now I just have this massive belly and I can't deny that I'm pregnant any longer!

"I've tried to not go too maternity, but at a certain point you've got to have room, you know?"

The 30-year-old actress - who is expecting her first child with fiancé Matt Rosenburg - has tried to stay in shape throughout her pregnancy and has been kept busy looking after her sister's two-year-old son Luca.

She has also been attending spin class SoulCycle which has become popular among A-listers.

The blonde beauty told US website Racked Miami: "I did SoulCycle through my whole pregnancy and I go on walks with friends...I've been active in general.

"Chasing my little nephew around and playing with him has been exercise enough."

Haylie first announced she was expecting a baby of her own on Instagram back in December.

She captioned an image of some baby Nike Jordan trainers: "Happiest girl in the world! Finally can let everyone know that Matty @mr_sts and I are expecting! #BabysFirstJordans. (sic)"