Reality TV star Kim Kardashian has given birth to her second child with rapper Kanye West.

"Kim Kardashian West and Kanye West welcomed the arrival of their son this morning. Mother and son are doing well," an announcement on her official website said on Saturday, reports aceshobwiz.com.

Kim's due date was on Christmas but she seemingly started having her contractions on Friday night as she hinted at an early delivery with a selfie that showed her bare baby bump.

"Ready whenever you are lol," the reality TV star captioned the picture.

Kim already has a daughter with Kanye named North West.

They have named the newborn Saint West.

This pregnancy was not easy for Kim. She had to undergo in vitro fertilization treatment because "conceiving on her own wasn't possible" after she had "three surgeries to repair her uterus" following North West's birth.

When she delivered her first child, she had a condition called placenta accrete, which prompted her doctor to "stick his entire arm in me and detach the placenta with his hand, scraping it away from my uterus with his fingernails".

It's unclear if it happened again, but if it did, she would need a hysterectomy.

"They think I'll have placenta accreta again, so if the placenta grows a little bit deeper than it did last time, then they are prepared to have my uterus removed, which is a little scary for me," she said.

Just a few days ago, she also underwent a painful medical procedure called an external cephalic version where doctors worked together to manually turn her baby from "breech" position.

It worked and she felt relieved "not to have the stress of thinking I need a C-section."