Woman Gives Birth To Twin Sister's Baby After Cancer Prevents Her From Pregnancy

'My bun. Her oven.'

Back in 2009, 32-year-old Allison Dinkelacker was living a happy life as mommy-to-be waiting for her first son Dylan to come out to this world. But life had other plans.

Thirty weeks into her pregnancy, Allison was diagnosed with Stage 3 breast cancer and had to start chemotherapy immediately. Numerous chemo sessions and exposure to radiation had a huge toll on her health and it seemed like the baby will never make it alive.

Then, on the day of her 33rd birthday, Allison delivered a healthy baby boy through emergency C-section. But the miracle was darkened by sad news — she was never to have children again.

Allison Dinkelacker (left) was told she will never be able to get pregnant again because her cancer was brought on by pregnancy hormones.

Allison was six years cancer-free when her oncologist announced the news.

Dinkelacker and her husband have always dreamt of having another child, a sibling for their son Dylan. Knowing that, Allison's twin sister Dawn Policastro just couldn't put up with the devastating fact. So she acted upon it.

'It doesn’t matter, because I am going to carry their child,' Allison recalls her twin sister, Dawn, fiercely announcing at the oncologist's office.

And the story couldn't have turned out more beautiful ...

Dawn became a gestational surrogate for her sister Allison, which means she underwent an embryo transfer process and carried the pregnancy to term.

According to their interview with Patch.com, both sisters are extremely close and live only three blocks away from each other. Photographer Allison Maffettone captured their bond in an adorable photo shoot.

On Aug. 5, Dawn gave birth to an 8-pound, 13-ounce baby boy named Hudson William Dinkelacker.

Here's an excerpt from the beautiful thank you post Allison dedicated to her sister:

"Our new son Hudson William Dinkelacker has arrived and he would not be here if it weren't for my amazing sister! [...] When most people would have given up during the struggles we endured, you just pushed through it all. Time and time again when we thought we should quit, you never gave up.

Dawn, you amaze me! You are my hero and I have never been more proud of you. You deserve a medal of courage, of compassion, and of selflessness.

How can we begin to thank you for the tremendous generosity and sacrifice you have so willingly bestowed these last few months? It's obvious that many people in your life think you are terrific. But probably no one knows the full extent of your caring and generous nature quite like we do."