Baby's Weird Sleep Habits

As a baby, my son, Darren, perspired while he slept. A lot. If he fell asleep in the car, I would sometimes pull over to dab at the moisture along his hairline. At first, I blamed the heat and humidity -- but he'd wake up with wet hair even in his air-conditioned bedroom.

Fearing the worst, I took him to the doctor. Turns out, the perspiration wasn't a big deal, since many infants sweat while they sleep. Babies have lots of other bizarre bedtime behaviors that can unnerve you. To ease your mind, we talked to experts about when the habits are harmless.

Seeing your baby hit his head against the crib mattress or rails as he's dozing off can certainly be unsettling. Fortunately, it's usually normal. Up to 20 percent of children are head-bangers, and boys are much more likely to do it than girls. It typically starts at around 6 months and slows or stops by age 3. The exact reason for head banging is unknown, but experts generally believe that it's a way to self-soothe. "In utero, a fetus is constantly being jostled to and fro, so a baby may be soothed by the rocking motion of head banging," says Rahil Briggs, Psy.D., a pediatric psychologist at Children's Hospital at Montefiore Medical Center, in New York City. It also may be done to distract from teething or earache pain.

Understandably, you may fear that your baby's habit could cause headaches, bruises, or even brain injury. Not likely. His noggin is tough, and if the banging becomes too painful, he'll stop on his own. So there's no need to pad the crib with bumpers or pillows -- after all, placing soft items in the crib increases risk of suffocation and SIDS.

Don't be surprised if your sleeping baby sometimes kicks her legs and punches her arms. She's not having a nightmare. "Babies have a very immature nervous system, and it's hard for them to control their reflexes and responses to environmental stimuli such as noise and temperature," says Kenneth Wible, M.D., a pediatrician with Children's Mercy Hospitals and Clinics, in Kansas City, Missouri. This means that those erratic movements are involuntary and usually harmless. To be sure, take your fingers and lightly hold down the arm or leg that's twitching. If the movement stops, no problem. But if it doesn't, if it occurs while your baby is awake, or if she has whole-body spasms, you should seek further evaluation, including a screening for epilepsy. Twitching that's not caused by a neurological disorder usually decreases between ages 2 and 4 months.

Although we like to think that only grown men snore, babies can produce the sound effect too. Snoring is usually the result of air passing through your little one's narrow nasal cavity or the back of the throat. The noise may happen because a baby has a cold or because his nasal passage is clogged with milk or baby food -- which can get pushed upward when he spits up. Use a suction bulb or saline drops to clear the nose.

Because sleep disorders like sleep apnea (a condition that causes momentary stops in breathing) can also trigger snoring, you should tell your pediatrician what's going on. Very loud snoring or snorting, gasping for breath, choking, and very restless sleep are signs of apnea and need immediate attention.

You may notice that your baby sometimes stops breathing for a few seconds while sleeping. It's normal for newborns to have "periodic breathing." They usually have a period of rapid breathing followed by a period of slow breathing, then a brief pause of up to ten seconds. The cycle then repeats. Breathing pauses happen because the part of your baby's brain that controls breathing is still developing, says Lewis Kass, M.D., a pediatric pulmonologist at Westchester Pediatric Pulmonology and Sleep Medicine, in Mount Kisco, New York. Unlike sleep apnea, periodic breathing doesn't cause snoring or struggles for breath. As long as your baby seems comfortable, isn't gasping for air, and her fingernails and lips don't change color, don't worry. Usually, by 4 to 6 months, the sleep-time breathing pattern becomes more regular.

As I learned, babies sometimes wake up sweaty. We all perspire during the transitions between different sleep stages, but infants sweat more because their sleep cycles are shorter, says Dr. Wible. Since your infant's head is his largest body part, it's where the most heat is lost; this may cause his forehead and hair to be damper than the rest of the body. Of course, babies can also get sweaty when they're too hot and their body is trying to cool down. To make sure your child doesn't overheat while he sleeps, keep his room between 60? and 70?F, and dress him the way you would be comfortable without covers. Call the pediatrician if he has a fever or another sign of sickness, such as lethargy. By 3 or 4 months, when their sleep cycles are longer, many babies won't sweat as much. Others, though, like my son, are just sweaty sleepers and continue to be into their toddler years and beyond. A good tip: To prevent overheating, avoid blankets and hats while baby's sleeping.

Originally published in the April 2011 issue of Parents magazine.