As the parents of a 4-month old, I think my wife Michaela and I can attest that you really don't need a study to tell us that parents of infants and toddlers sleep less than other parents. Nonetheless, mattress company Amerisleep found, unsurprisingly, in a two-year study, that parents with kids zero-1 years old sleep least.
HOWEVER! This is surprising (and worrisome for me since I have a son), the study found that fathers of sons aged 13-17 years old sleep just as little as those with infants. Maybe the dads are just stating up late playing video games with their teenage sons!
Check out the full study HERE!