A woman whose baby was delivered 12 weeks early so she could begin intensive treatment for breast cancer without harming the child has said she would have made some very different decisions if she had known her daughter would die.

Heidi Loughlin, 32, had been diagnosed last September with inflammatory breast cancer, a rare and fast-spreading form of the condition. Doctors said she could terminate her pregnancy to undergo aggressive treatment using the drug Herceptin, which can harm a foetus, but she declined, beginning a milder treatment instead.

When doctors found this had failed to halt the cancer’s spread, Loughlin, who has two sons, opted to have her daughter, Ally Louise, delivered early before beginning the treatment with Herceptin.

Speaking about the difficult decisions she faced last year, she told the BBC: “If I knew she wasn’t going to make it ... I would have kept her in my tummy.

The Somerset police officer, from Portishead, near Bristol, spoke of how she missed her daughter, and how her two sons kept her going.

“With her having such a great prognosis at 28 weeks, it just made sense. And maybe some people would have done things differently but I wanted to make it right for all of them,” she added.

“She’s in my mind all the time. I want her to be proud of me. She’s my little girl.”

All had initially appeared to be going well and Loughlin had announced the birth in December with a post on her blog, saying: “She came out foot first and is breathing on her own. She weighs 2lb 5ozs. She has a Loughlin nose and she has more hair than me!!!”

Four days later she updated her blog, saying her daughter was “doing so well and kicking arse”. However, another post came five days later, with a poem announcing her death.

“We kissed you, we cuddled you, we tickled your feet,” it read. “And I know again one day we’ll meet.”

Loughlin told the BBC that, in the hours after her daughter’s death, she had questioned the point of having chemotherapy but had been supported by her “completely selfless” partner and was making plans for the future.

“It’s about wanting whatever time I have left to mean something and not be swallowed up by the devastation of losing Ally,” she said.

“To wake up and breathe was difficult at that point – then I would think it’s for the boys and put one foot in front of the other,” she said.