Changing insurance after delivery?

Hi,

My wife and I had a baby two weeks ago. Right now, we are together in a UMR PPO Gold plan with my employer (in CO) that has paid most of the labor and delivery costs, but has a $800/month premium. If we added our daughter to the plan, we would pay a $1500/month premium, something that is too much for us. We would like to ask a couple questions:

Now that hospital expenses for my wife are mostly over and since we are within the 30-day window to change our health insurance, we were thinking that my wife should go back to her employer’s insurance, which is free but doesn’t have good coverages. However, we are afraid that this new insurance could apply retroactively to the birthdate and then we would have to pay all labor and delivery expenses with the new insurance. Is that how it works or am I missing something? From what day would the new insurance apply?

Similar situation but with the baby. We are satisfied with the estimate from the hospital after the delivery and the hospital stay (around $2,000). But we are considering “downgrading” to a UMR PPO Silver plan with more deductibles but lower premium ($600). Would this change apply retroactively to the birthdate and possibly change the amount that we would have to pay for hospital expenses or would the new insurance start covering from now on?

What do you think would be the best option in this situation? Is “downgrading” insurance after delivery not the best option to avoid high premiums and save some money? Is it better to wait until open enrollment period?

We would really appreciate if somebody could help us with these questions. Thank you so much in advance.