Each birthday could be the last for twins Alfie and Arthur - which left their mother determined to make them all special.
But Emma Louise Lowe was heartbroken when they received no cards other than from her and their siblings.
However, when the twins, who have Down's syndrome, turned five, hundreds of birthday cards arrived in the post.
It is because a Welsh charity appealed for the twins to be sent cards to make them feel "extra special".
Since then, thousands have been sent to children who may otherwise receive none by a Church Village charity.
Follow Your Dreams set up the Birthday Smiles initiative 18 months ago and has helped make birthdays extra special for 84 children in the past year.
"Every birthday when they received one or two cards, it broke my heart," explained Ms Lowe, from Preston.
She described people "gradually moving away from you" as you bring up disabled children and "you feel like you're on your own".
"When a child has a disability or so many medical needs, reaching a birthday is a milestone," she added.
"I want to make every year I have with them extra special."
Alfie and Arthur are ambassadors for the Follow Your Dreams charity, which encourages children with disabilities to be ambitious and pursue activities they are interested in such as sports and drama.
The idea for Birthday Smiles came about after its chief executive Diane Blackmore called Ms Lowe and said they were sending the boys cards.
"She broke down in tears and said she was really grateful we were going to send them a card," she said.
"I thought it was strange as I received many cards as a child, some I have kept now.
"But it turned out family and friends didn't send the boys cards and this was heartbreaking."
An appeal on social media had a "huge response" and cards and presents were sent to Alfie and Arthur, many with handwritten notes from parents and children who had experienced similar.
Ms Blackmore added: "I lost my dad and nan and these (cards from them) become memories.
"They can be treasured forever and help parents feel their children are really loved by others."
The charity has now sent thousands of cards out and hopes groups such as youth clubs, Brownies, Scouts and schools will get involved in the initiative.