Pregnant mum who sacrificed life for unborn baby lives on as voice of child's iPad app

A mum who sacrificed herself for her unborn baby lives on from beyond the grave as the voice of her girl's educational toy.

Liz Joice made the ultimate sacrifice when she was diagnosed with cancer of the spine by shunning surgery so her unborn child could survive.

Her daughter Lily was born by Caesarean prematurely at 34 weeks.

Liz, who defied doctors who thought she would not be able to conceive because of her cancer, lost her fight for life less than seven weeks later.

Now the remarkable story of how the 36-year-old gave up her life to leave her husband Max with an "amazing" gift features in a documentary 40 Weeks.

In the documentary, which charts expectant couple's up until the point of birth, Liz of New York, says: "There’s never going to be anything in my life that I’m going to do that is more amazing than this."

Liz was diagnosed with a rare form of cancer called sarcoma in 2010, reports the New York Post. Doctors believed she would likely to be unable to conceive because chemotherapy sent her body into an early menopause.

But the joy of finding out they were expecting was shattered the day after Liz's 12 week scan when it was revealed the cancer in her spine had returned.

If medics were to perform a full MRI scan to trace all possible tumors - which might lead to invasive treatment - they would need to terminate the pregnancy.

However, Liz refused and underwent surgery on the tumor in her spine.

"It’s mama-bear mode. You’re messing with my cub, and I’m going to take you out," she says in the documentary when talking about confronting her illness.

Once Lily was born tests showed Liz, who described the news of her second diagnosis as "the world's cruelest joke" also had tumours in her abdomen, lung and heart.

"We said our goodbyes,” Max, 35, told the New York Post.

"It was like something out of a movie. We sat there and cried. We tried to tell stories, talk about all the great things."

Because of the couple's involvement in 40 Weeks director Christopher Henze built up around 60 hours of footage of Liz, some of which has been used to create educational aids for Lily, now 16 months, on her iPad.

It includes a 13-minute-long video called Like A Baby Einstein where footage of Liz has been mixed with other children's TV shows such as Curious George, Yo Gabba Gabba and Barney and Friends.

The app helps Lily to recognise different foods and as Curious George counts past 10, Liz can be seen saying the numbers which come from her happily declaring how many weeks pregnant she is.

The app also features a song about cleaning up after Liz accidentally spilled a jar of tomato sauce on camera.

The director has held back footage including an emotional piece to camera by Liz in which she tells her then unborn baby about her cancer returning.

She said: "Regardless of whatever happens to me, going through this to bring you here is always going to be worth it, no question. I don’t want that to be hard on you."

Mr Henze said: “Right now it’s about shapes and sounds and colours . . . [with] her mother’s image and her mother’s voice, So she knows what her mother looks like, knows what her mother sounds like.

"Our plan is to keep crafting pieces to allow Lily more an