Supermum Caesarean a fortnight ago. He had to be moved to a special care baby unit after suffering from problems but he is now back home with his brothers and sisters.
Tania has Caitlin, 14, Harry, 11, Eddie, nine, Sid, eight, Patrick, six, Oliver, four, Joseph, three, twins Anna and Libby, two, and Isobel, 15 months with husband Mike, and Ben, 21, and Stephanie, 19, from a previous relationship.
When asked if she'd like even more children, Tania told Parentdish: "Who knows? You never know what is around the corner so we don't plan one way or another. With eight losses we're all too aware that falling pregnant doesn't necessarily mean holding a baby nine months down the line.
"We never sit and say, 'In six months we'll try for another so we can have a baby next year'. Life doesn't work that way. We say that we're happy to have more if we can, but we realise how lucky we already are if we can't."
Tania and Mike make a living by sharing their experiences on their hugely successful website Larger Family Life, which has 114,000 subscribers, in addition to media and public speaking work.
Tania said: "We want the children to be happy, but also responsible and considerate. They will learn you don't get something for nothing in this life.
"We are not wealthy and don't have extraordinary jobs but we work despite the fact it would be more profitable not to. It is none of anyone's business how many children I choose to have."
The Sullivans spend £200-a-week on shopping, which includes 21 loaves of bread and 84 pints of milk. Nine hens provide eggs – and the children are all home schooled.
But they don't go without. Last summer's family holiday was an eight-week excursion across France and Italy in the family car – a 17-seater minibus.
For now, they are enjoying their latest addition to the family, but they have their eye on the future.
Mike said: "We have big plans – a larger house and land to grow vegetables and keep livestock. It's a dream but hard work will get us there."