No one plans on having their newborn spend time in the neonatal intensive care unit (NICU), but roughly 78 out of every 1,000 babies born in the U.S. each year stay in these specialized nurseries. Most of them are premature babies, as 1 in 10 newborns are born before 37 weeks in the U.S. So it’s worth learning about the place all preemies visit upon arrival. Here’s a quick guide to what you can expect while your baby is there.