Baby monitors shouldn't be used as a substitute for adult supervision. They should be considered as an extra set of ears—and, in some cases, eyes—that help parents and caregivers keep tabs on sleeping babies. Using one can alert you to a situation before it becomes serious, for example, if your baby is coughing, crying, or making some other sign of distress. Experts warn that you can't rely on a monitor to prevent Sudden Infant Death Syndrome (SIDS).
It really depends on what you feel most comfortable with. There are audio monitors that allow you to listen to any noise coming from the nursery, vital monitors that track sleep and breathing and video monitors that add sight to sound. Babylist parents overwhelmingly choose video monitors. The security of seeing what your child is up to—like if they’ve gotten tangled in their swaddle, pulled their diaper off or climbed out of the crib—can be worth the extra cost of a video monitor.