In 1995, a study was done on infants’ oxygenation levels in their car seats. Normal oxygenation levels – that is, the amount of oxygen circulating in the blood stream attached to red blood cells – range between 97-99% in a healthy term infant in optimal positioning. Any oxygenation level below about 90% is considered “hypoxia” – the baby is not receiving enough oxygen, and brain damage can result if that level is sustained. Shockingly, healthy, full-term newborns placed in correctly positioned car seats had oxygen levels that went as low as 83.7%. In the hospital, such levels would bring teams of nurses scrambling to the infant’s rescue. While not all infants’ oxygenation levels reached such depths, there was a consistent finding that the longer the baby spent in the car seat, the lower their oxygen levels would go, until the baby was removed from the seat.
The study was repeated in 2005, with the same results.You know these parents should really consider buying a sling, a mei tai or another safe baby carrier as it makes it easier to go about your biz, play with the older children while keeping the newborn safe and being nurtured. I LOVE my sling and its something I cannot live without it simplifies my life and its easy on me to take care of an overly active toddler while still giving my newborn the attention it needs.
PS. not every sling is safe check this well written article about safety
 by "THESE" parents I mean the parents featured on the show not the parents featured in the study.