How much do your kids cost you every month? & Hospital Bills?

$o.oo they are older now and on their own. DGS has special needs so I can not tell you.

It depends on the individual child and what type of insurance you have and where you do your shopping and where you live.and what you consider necesities for your child. Everyone's definition is different.
I think if you google it you can get some info on national averages though

Including mortgage (if we didn't have 5 kids we would live smaller so I include a fraction of our mortgage), extra electricity/water, clothes, food, and entertainment I would say $800/month/child easy. Infants not so much especially if you breastfeed, unless you buy a set of nursery furniture you will only use for a few years. That doesn't include savings for college.
Hospital bills will vary widely with insurance. I paid between $25 (yes only $25!) and $4500 for my 5 for prenatal care and delivery, all with insurance.

Well we paid around $300 for prenatal visits and hospital stay with my DD(she was born in May). We bottle feed and formula is usually about $140/month. Diapers (that really depends on the brand you buy and size) are usually about $50/month, we use luvs. Doctor appointment copay is $30 each visit and there is a bunch of those the first year. Plus we are starting to see a nephrologist every six months with my DD(that's another $30). I'm sure there is more, but I can't of anything else at the moment.

My son went to daycare when he was 6 weeks parttime first, costing $300/month, than fulltime at one year, costing $700/month.

When he started Kindergarten at age 6 he was in afterschool care and until now in 45h grade, its cost me $300/month.

I got health insurance a month before he was born and it covered his birth.
Visits to doctors are copay for $15.
Before that all my medical visits where paid in cash. My dr. let me pay $100/per visit, as long as it was paid in cash.

Not sure of all the things I have paid for over the years, from diapers, to food, new-used-replacement clothes, to activties at school and out of school, toys, books, day and overnight weekly trips somewhere, bedroom furniture, electronic things, school supplies, gifts for friends for bdays.