Month 4

Milestones this month

Month four is when your baby transforms from a sweet, snuggly newborn into a small human with opinions, preferences, and an insatiable curiosity about the world. They are more interactive than ever — and they want you to know it.

Reaching and grasping are now deliberate. Your baby will spot something interesting, reach for it with both hands, grab it, and immediately put it in their mouth. This is not random — mouthing is how babies this age explore texture, shape, and temperature. Everything goes in the mouth: toys, fingers, your hair, the remote control, their own feet (once they discover those). This is normal and healthy, not a sign of teething (though drooling may increase dramatically around now, which confuses everyone).

Rolling may happen this month — typically tummy to back first, since it requires less coordination. Some babies roll once and then do not bother again for weeks. Others become rolling machines overnight. Either pattern is normal. If your baby can roll in any direction, it is time to stop swaddling — their arms need to be free to push up if they roll onto their stomach during sleep.

Your baby is becoming a social butterfly. They babble with strings of sounds, blow bubbles, squeal with delight, and may begin to show different cries for different needs (hungry, tired, bored, overstimulated). They recognize familiar people and may become hesitant around strangers — the earliest hint of stranger awareness.

Attention span is growing. Your baby can now focus on a toy or activity for several minutes, and they are learning cause and effect: shake the rattle and it makes noise, kick the play gym and the toys swing. You can almost see the neural connections forming in real time.

Every baby develops at their own pace — these are general guidelines, not deadlines.

Sleep guide

Let us address the elephant in the nursery: the 4-month sleep regression. If your baby was starting to sleep in longer stretches and has suddenly reverted to waking every 1 to 2 hours, you are not imagining it, and you did not do anything wrong. This regression is a permanent change in your baby's sleep architecture — they are transitioning from newborn sleep cycles (which have only two stages) to adult-like sleep cycles (which have four). During this transition, your baby wakes more frequently between cycles and may not know how to fall back asleep without help.

This is the most brutal sleep disruption many parents face, and it can last 2 to 6 weeks. Strategies that help: keep the room dark, maintain your bedtime routine with fierce consistency, offer comfort when your baby wakes (patting, shushing, brief feeding) but try to put them down drowsy when possible, and take shifts with your partner. If your baby was sleeping in a swaddle and is now rolling, transition to a sleep sack with arms free.

Total sleep is around 12 to 16 hours per day. Daytime naps are typically 3 to 4 naps, though they may be shorter and more irregular during the regression. Watch for sleepy cues 60 to 90 minutes after waking — most 4-month-olds cannot stay awake much longer than that without becoming overtired.

Safe sleep guidelines remain non-negotiable: back to sleep, firm surface, nothing in the crib. If your baby rolls to their stomach during sleep and can roll both ways, you do not need to flip them back — but always start them on their back.

This regression ends. The sleep gets better. Hold on.

Feeding guide

Your baby is eating with more enthusiasm and efficiency than ever. Breastfed babies typically feed 5 to 6 times per day, and bottle-fed babies are taking 5 to 7 ounces per feeding. Total daily intake for formula-fed babies is usually around 24 to 32 ounces.

Distracted feeding becomes a real thing this month. Your baby is so interested in the world that they may pop off the breast or push the bottle away to look at the dog, the ceiling fan, or your face. Feeding in a quiet, dim room can help if distractibility is making feeds frustratingly short.

Growth spurts can occur around 4 months, leading to a few days of increased hunger. If you are breastfeeding, your baby may want to nurse more frequently — this is not a sign that your supply is failing. It is your baby signaling your body to increase production.

You may notice people suggesting that it is time to start solid food. The AAP recommends waiting until around 6 months for most babies. Signs that your baby is ready for solids (which typically appear closer to 6 months) include sitting with minimal support, showing interest in food you are eating, loss of the tongue-thrust reflex, and good head control. Talk to your pediatrician at the 4-month visit about the timeline that makes sense for your baby.

The 4-month well-child visit includes another round of vaccines. Your baby may be fussy and have a mild fever afterward — this is a normal immune response. Comfort nursing or an extra bottle, infant acetaminophen if recommended by your pediatrician, and extra snuggles usually do the trick.