Is it okay for a 8 day old baby to sleep overnight in car seat?

Not a good idea.: While we used to think that being in a car seat would help prevent reflux, it actually doesn't work because the flexion puts oressure on the diaphragm. To reduce the risk of sids by 50%, babies should be put in their cribs on their backs on a hard mattress with no loose bedding. Sleep consolidation occurs from 1-4 mos. If they are put in their cribs drowsy but awake. See www.Aap.Org.

Car seat: As long as the car seat is safe(has not been recalled) and in a safe place in the home (never leave baby in car overnight) like next to your bed then it is okay. The baby will waken to be fed i assume and having the baby in the same room as you is handy.