It is a choice that no expecting mother should be forced to make: keep a baby or receive treatment for cancer.

Thanks to help from a leading cancer researcher in Ottawa, some women have been saved from this incredibly difficult decision.

In the past, women like 31-year-old Jillian O'Connor -- an Ottawa native who is pregnant with her third child and has Stage 4 breast cancer -- may have been advised to terminate her pregnancy in order to receive treatment.

But Dr. Mark Clemons, an oncologist at the Ottawa Hospital, designed a plan that would allow O'Connor to receive chemotherapy and deliver a normal, healthy child.

"The hope is that we are giving her the best treatment in the world to give her the best chance of not only seeing the baby born, but watching this baby grow up," he told CTV Ottawa.

Dr. Clemons is part of the Tender Loving Research program at the Ottawa Hospital, which is working on genetic research as well as personalized therapies for cancer treatment.

The pregnancy has been an emotional rollercoaster for O'Connor –- she discovered a lump in her breast after 16 weeks.

Following a total mastectomy, O'Connor received a type of chemotherapy that does not cross the placenta, and she is ecstatic about the results so far.

“They thought that maybe the side-effects would be a low birth weight, but it's exceeding all expectations,” she said.

"It's doing so wonderfully," she added.

O'Connor is counting down the days to when she will be able to hold her newborn baby in her arms. She is scheduled to have labour induced on Feb. 1.

Breast cancer is rare during pregnancy –- it develops in about 1 in 3,000 expectant mothers. But the risk of developing breast cancer increases in older women. Approximately 50 per cent of cases are found in women 65 or older, and more than 30 per cent occur in women over 70.

Dr. Clemons treats about two pregnant women a year in Ottawa who have breast cancer, and the aim is always to deliver a healthy baby.

And even though O'Connor's cancer is incurable, Dr. Clemons' treatment has given her another option –- a chance at life alongside her kids.

"I want to play with my kids and give them a new brother, or sister, and just live life and be a mom," she said.

With a report from CTV Ottawa