Harriet and Nicholas with baby Maddison who was born 12 weeks early (Picture: Harriet Elsdon/ SWNS)

A newborn baby who was 12 weeks premature helped to save her mum’s life as doctors discovered a cancerous tumour.

Harriet Elsdon, 32, was told by medics that it “might have been too late” if she had given birth on her planned due date.

The mum-of-three was diagnosed after visiting her daughter, Maddison Wilmshurst-Smith, in the ICU at Broomfield Hospital, Chelmsford, Essex.

She was experiencing stomach pain so bad that she struggled to walk when neonatal staff told her to seek medical attention.

After a scan, doctors found that a cyst on her right ovary – which had been initially detected at her 20-week scan back – was growing.

The doctors had scheduled in check-up scan for when Harriet was 29 weeks along, but baby Maddison arrived earlier.

The new mum was too focused on her baby to worry about herself (Picture: Harriet Elsdon/SWNS)

During the procedure, they found the cyst had burst and was in fact cancerous.

The mum-of-three, who works as an administrator, had an operation to remove her right ovary and one fallopian tube. She started chemotherapy just weeks later.