Katie talked about life with 12-year-old son Harvey, who suffers from a range of disorders, during her FUBAR Radio show this morning (8 July).
"Having a child with disabilities is hard work and I would not change it for anything," said 36-year-old Katie. "Harvey has so much medication each day and if he doesn't, he'd die basically."
Harvey has a string of disabilities including blindness, autism, ADHD and Prader-Willi syndrome (a genetic disorder meaning he's likely to eat to excess).
Former glamour model Katie told listeners that Harvey - whose father is her former footballer Dwight Yorke - gets "easier" to look after the older he becomes.
"I have a nanny Monday to Friday for Harvey, but now he's getting older, it's getting easier," she said. "He's getting more vocal."
Katie, who is also mum to nine-year-old son Junior and six-year-old daughter Princess from her marriage to Peter Andre, as well as 10-month-old son Jett with current husband Kieran Hayler, said she sometimes feels "guilty" when Harvey goes away on school trips.
"Harvey can board at his school but I like him to come home," Katie explained. "He's going on a two-week school holiday soon and I feel so guilty, but he went camping last week and he absolutely loved it.
"Harvey's a 12-year-old going through puberty. A normal 12-year-old would be getting themselves bathed and washed. He goes to school an hour away from where he lives instead of a local school because I want the best for him."
Katie, who is expecting her fifth child - a girl - with Kieran, said her experience with Harvey has made her "appreciate" what other families have to go through.
"Being a full time mum is a hard job," Katie continued. "When I'm out and I see families with kids in wheelchairs, I can appreciate how hard it is to get them ready and get them in the car etc. It's not easy but you're never a failure. Always talk about it. There is help out there if you look for it."
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