Newborns are more fragile than most new parents expect. Their immune systems are immature, their neck muscles can’t support their heads, and their tiny bodies react to things that are perfectly safe for older children. Knowing what to avoid is just as important as knowing what to do, and some of the most common mistakes carry serious consequences.
Putting Anything Soft in the Crib
Blankets, pillows, stuffed animals, and bumper pads all increase the risk of suffocation and sudden infant death syndrome (SIDS). A safe sleep space has exactly three things: a firm, flat mattress, a fitted sheet, and your baby. That’s it.
Always place your newborn on their back for every sleep, including naps. Stomach sleeping and side sleeping significantly raise the risk of SIDS. This applies even if your baby seems to sleep more soundly on their tummy. If they roll onto their stomach on their own (which won’t happen in the first few weeks), that’s a different situation, but until then, back sleeping is the standard.
Giving Water, Honey, or Aspirin
A newborn’s stomach is tiny and their body chemistry is delicate. Plain water is dangerous for babies under 6 months because it dilutes the sodium in their bloodstream, a condition called water intoxication. This can cause seizures, coma, and permanent brain damage. Breast milk and properly mixed formula already contain all the water your baby needs.
Honey is off-limits until 12 months. It can contain spores that cause infant botulism, a severe form of food poisoning. Don’t add honey to food, water, formula, or a pacifier.
Never give a baby aspirin. It’s linked to Reye’s syndrome, a rare but potentially fatal condition that causes swelling in the brain and liver, particularly in children fighting a viral illness. If your newborn needs pain or fever relief, your pediatrician will recommend a safer alternative appropriate for their age.
Shaking or Jostling the Baby
A newborn’s head is large relative to their body, and their neck muscles are far too weak to stabilize it. The skull hasn’t fully hardened yet, and the brain has a higher water content than an adult’s. All of this means that even brief, forceful shaking can cause blood vessels inside the skull to tear, leading to bleeding around the brain, swelling, and permanent injury.
This doesn’t mean you need to be afraid of normal, gentle handling. The danger comes from violent back-and-forth motion, the kind that can happen when a caregiver is frustrated by inconsolable crying. If you feel overwhelmed, putting the baby down in a safe place like their crib and stepping away for a few minutes is always the right call.
Exposing Them to Crowds Too Soon
Newborns haven’t had time to build immune defenses, making them significantly more vulnerable to infections from both bacteria and viruses. Johns Hopkins Medicine recommends that extended family and friends wait two to three months before visiting, and that parents avoid crowded places like malls, airplanes, and theme parks until the baby’s immune system has had more time to develop.
Respiratory syncytial virus (RSV), flu, and whooping cough can all be life-threatening for young infants. During flu season, anyone who will be near the baby should be up to date on their vaccinations. And anyone who is currently sick, even with what seems like a mild cold, should wait to visit.
Propping a Bottle
Leaning a bottle against a pillow or blanket so the baby can feed without being held is a choking hazard. Liquid keeps flowing whether the baby is ready to swallow or not, and if they fall asleep or can’t keep up, they can inhale milk into their lungs. Propped bottles also cause overfeeding, since the baby can’t signal that they’re full.
There’s another risk that’s less obvious: when a baby drinks while lying flat with a propped bottle, liquid pools at the back of their mouth and can travel into the ear canals. Repeated ear infections from this can lead to hearing loss that affects speech and language development.
Submerging Them in a Bath Too Early
Until the umbilical cord stump falls off, your baby should only get sponge baths. Submerging the cord area in water increases the risk of infection. Clean around the stump with warm water and mild soap during each diaper change, and gently pat the area dry. Once the stump falls off on its own (usually within one to three weeks), tub baths are fine.
Dressing Them in Bulky Coats in a Car Seat
A puffy winter coat creates a gap between your baby’s body and the car seat harness. The harness feels snug over the coat, but in a crash, the coat compresses and the straps are suddenly too loose to protect your child. The National Highway Traffic Safety Administration recommends using thin, lightweight fleece layers instead. For extra warmth, drape a blanket over the buckled harness or put a coat on backward over it.
Exposing Them to Smoke or Direct Sunlight
Secondhand smoke is one of the most clearly established risk factors for SIDS. The chemicals in tobacco smoke interfere with the part of the brain that regulates an infant’s breathing. Babies exposed to secondhand smoke after birth are also at higher risk for pneumonia, bronchitis, ear infections, and asthma. Infants who die from SIDS have measurably higher concentrations of nicotine in their lungs than infants who die from other causes. No amount of secondhand smoke exposure is considered safe for a newborn.
Direct sunlight is also a problem. The FDA and the American Academy of Pediatrics recommend keeping babies under 6 months out of direct sun entirely, and sunscreen is not recommended for this age group without a pediatrician’s guidance. Instead, keep your baby in the shade, dress them in lightweight long sleeves and pants, and use a wide-brimmed hat that covers the ears and neck. Avoid being outside during peak sun hours, between 10 a.m. and 2 p.m.
Ignoring a Fever
For a baby under 3 months old, a rectal temperature of 100.4°F (38°C) or higher is a medical emergency. At this age, a fever can be the only visible sign of a serious bacterial infection, and the immune system isn’t mature enough to fight it without help. Don’t wait to see if the fever breaks on its own, and don’t try to treat it at home. This is a situation that requires immediate medical attention, every time.