I personally dont but my grandparents had 2 sets 11 months apart. Nan reckons that as long as you have good support it works ok. They also had a 16 month old when the first set were born. Nan and Pop had a roster where if it was 1 set it was his turn if it was the other set it was her turn. They went on to have 3 more singletons after the second set of twins.