On Sunday, 18-year-old Joanna Marisela Delgado swerved over the middle of the lane while she was driving in California and collided with an oncoming car.

She was in her third trimester, and paramedics rushed to deliver the baby via caesarean section on the roadside.

The driver of the other vehicle – 24-year-old Adriana Solorio Romero – was pronounced dead at the scene.

A 10-year-old boy who was also in the car with Joanna was rushed to hospital, where he remains in a critical condition.

Shortly after welcoming her baby girl, Joanna died from her injuries.

Now, police have confirmed that the baby girl - who was named Mila Rose - has also died in hospital.

According to ABC News, Fresno County Sheriff's spokesman Tony Botti said the newborn died early Monday in hospital.

Family and friends have begun to pay tribute to Joanna, who has been described as "beautiful, loving and outgoing."

"I was so excited for her and her pregnancy, I was only happy she was happy. I can't believe she's gone, it seems so unreal," friend Ashley Ayala wrote

"My prayers go out to all her family and loved ones...I love you Jojo. Rest easy with baby Mila Rose."

"You will be missed dearly by everyone who knew you," Joanna's cousin Soleil Ochoa wrote.