Well-Baby Checkup: 4 Months

Development and milestones

The healthcare provider will ask questions about your baby. They will watch your baby to get an idea of their development. By this visit, most babies do these:

• Holding up their head

• Use their arm to swing at toys

• Holds a toy when you put it in their hand

• Makes sounds like "oooo" and "aahh"

• Chuckles when you try to make them laugh

• Turns head towards the sound of your voice

• Brings hands to mouth

• Smiling on their own to get attention from a caregiver

Feeding tips

To help your baby eat well:

• Keep feeding your baby with breastmilk or formula. At night, feed when your baby wakes. At this age, there may be longer times of sleep without any feeding. This is OK. Just make sure your baby is getting enough to drink during the day and is growing well.

• Breastfeeding sessions should last around 10 to 15 minutes. With a bottle, slowly increase the amount of breastmilk or formula you give your baby. Most babies will drink about 4 to 6 ounces. But this can vary.

• If you’re concerned about how much or how often your baby eats, talk with the healthcare provider.

• Ask the healthcare provider if your baby should take vitamin D.

• Ask when you should start feeding the baby solid foods. Healthy full-term babies may start eating soft or pureed food around 4 months of age.

• Many babies still spit up after feeding at 4 months old. In most cases, this is normal. Talk with the healthcare provider if you see a sudden change in your baby’s feeding habits.

Hygiene tips

• Some babies poop a few times a day. Others poop as little as once every 2 to 3 days. Anything in this range is normal.

• It’s fine if your baby poops less often than every 2 to 3 days if the baby is otherwise healthy. But if your baby also becomes fussy, spits up more than normal, eats less than normal, or has very hard poop, tell the healthcare provider. Your baby may be constipated. This means they are unable to have a bowel movement.

• Your baby’s poop may range in color from mustard yellow to brown to green. If your baby has started eating solid foods, the poop will change in both texture and color. 

• Bathe your baby about 3 times a week. Bathing too often can dry out their skin.

Sleeping tips

At 4 months of age, most babies sleep around 15 to 18 hours each day. Babies of this age sleep for short spurts throughout the day, rather than for hours at a time. This will likely change over the next few months as your baby settles into regular nap times. Also, it’s normal for the baby to be fussy before going to bed for the night (around 6 p.m. to 9 p.m.). To help your baby sleep safely and soundly:

• Place the baby on their back for all sleeping until the child is 1 year old. Use a firm, flat, sleep surface. This can decrease the risk for SIDS (sudden infant death syndrome). It lowers the risk of breathing in fluids (aspiration) and choking. Never place the baby on their side or stomach for sleep or naps. If the baby is awake, allow the child time on their tummy as long as there is supervision. This helps the child build strong tummy and neck muscles. This will also help reduce flattening of the head. This can happen when babies spend too much time on their backs.

• Ask the healthcare provider if you should let your baby sleep with a pacifier. Sleeping with a pacifier has been shown to lower the risk for SIDS. But it should not be offered until after breastfeeding has been established. If your baby doesn't want the pacifier, don't try to force them to take it.

• Wrapping the baby tightly in a blanket (swaddling) at this age could be dangerous. If a baby is swaddled and rolls onto their stomach, they could suffocate. Don't use swaddling blankets. Instead, use a blanket sleeper to keep your baby warm with the arms free.

• Don't put a crib bumper, pillow, loose blankets, or stuffed animals in the crib. These could suffocate the baby.

• Don't put your baby on a couch or armchair for sleep. Sleeping on a couch or armchair puts the baby at a much higher risk for death, including SIDS.

• Don't use infant seats, car seats, strollers, infant carriers, or infant swings for routine sleep and daily naps. These may lead to blockage (obstruction) of a baby's airway or suffocation.

• Don't share a bed (co-sleep) with your baby. Bed-sharing has been shown to raise the risk for SIDS. The American Academy of Pediatrics advises that babies sleep in the same room as their parents, close to their parents' bed, but in a separate bed or crib appropriate for babies. This sleeping setup is advised ideally for the baby's first year. But it should be maintained for at least the first 6 months. 

• Always place cribs, bassinets, and play yards in hazard-free areas. This is to reduce the risk of strangulation. Make sure there are no dangling cords, wires, or window coverings. 

• This is a good age to start a bedtime routine. By doing the same things each night before bed, the baby learns when it’s time to go to sleep. For example, your bedtime routine could be a bath, followed by a feeding, followed by being put down to sleep.

• It’s OK to let your baby cry in bed. This can help your baby learn to sleep through the night. Talk with the healthcare provider about how long to let the crying continue before you go in.

• If you have trouble getting your baby to sleep, ask the healthcare provider for tips.

Safety tips

• By this age, babies begin putting things in their mouths. Don’t let your baby have access to anything small enough to choke on. As a rule, an item small enough to fit inside a toilet paper tube can cause a child to choke.

• When you take the baby outside, don't stay too long in direct sunlight. Keep the baby covered or go in the shade. Ask your baby’s healthcare provider if it’s OK to put sunscreen on your baby’s skin.

• In the car, always put the baby in a rear-facing car seat. This should be secured in the back seat. Follow the directions that come with the car seat. Never leave the baby alone in the car.

• Don’t leave the baby on a high surface, such as a table, bed, or couch. They could fall and get hurt. Also, don’t place the baby in a bouncy seat on a high surface.

• Walkers with wheels are not advised. Stationary (not moving) activity stations are safer. Talk to the healthcare provider if you have questions about which toys and equipment are safe for your baby. 

• Older siblings can hold and play with the baby as long as an adult supervises. 

Vaccines

Based on recommendations from the CDC, at this visit your baby may receive the below vaccines:

• Diphtheria, tetanus, and pertussis

• Haemophilus influenzae type b

• Pneumococcus

• Polio

• Rotavirus

Having your baby fully vaccinated will also help lower your baby's risk for SIDS.

Going back to work

You may have already returned to work or are preparing to do so soon. Either way, it’s normal to feel anxious or guilty about leaving your baby in someone else’s care. These tips may help with the process:

• Share your concerns with your partner. Work together to form a schedule that balances jobs and childcare.

• Ask friends or relatives with kids to recommend a caregiver or daycare center.

• Before leaving the baby with someone, choose carefully. Watch how caregivers interact with your baby. Ask questions and check references. Get to know your baby’s caregivers so you can develop a trusting relationship.

• Always say goodbye to your baby, and say that you will return at a certain time. Even a child this young will understand your reassuring tone.

• If you’re breastfeeding, talk with your baby’s healthcare provider or a lactation consultant about how to keep doing so. Many hospitals offer return-to-work classes and support groups for breastfeeding parents.