Parent guides · 3 months
Your fourth month, day by day
Days 91 to 120: laughs, grabbing, first rolls, a steadier head, depth and color, sleep reorganizing, the drowsy-but-awake question, and the 4-month checkup, with one new thing to try every day.
Every note draws on the 3-month guide and cites its sources. Babies don’t keep calendars: read each day as “around now”, and let your pediatrician’s read of your baby beat any note.
Week 13: month four begins
Laughs, grabbing, first rolls, a steadier head, depth and color, and new sounds.
Day 91Month fourA new month and a new list. What the 4-month milestones mean, what's on the 6-month list ahead, corrected age, and a first reach-and-grab on the floor.Try: Reach-and-grab
Day 92LaughsLaughter first shows up at about 4 months on average, and your own laugh is part of how a baby learns what's funny. Chuckles, looking away, and the raspberry game.Try: Raspberry laugh game
Day 93GrabbingReaching starts at about 3 months and grasping follows by 4: the mitten grip, why everything heads for the mouth, when the pincer grasp comes, and a toe-discovery game.Try: Toe discovery
Day 94First rollsRolling usually starts around 3 to 4 months, tummy to back first. What changes for sleep when it does, why no raised surface is safe for a second, and a roll-over helper on the floor.Try: Roll-over helper
Day 95A steadier headBy 4 months most babies hold their head steady when held. How tummy time builds it, the one sign to raise between 4 and 7 months, and a look-around game on the floor.Try: Tummy-time look-around
Day 96Depth and colorBy 4 months babies see colors and shades better and love circular patterns; depth vision shows up in the lab at about 16 weeks. Why seeing an edge isn't fearing one.Try: Color and pattern look
Day 97Fourteen weeks: new soundsStrange new sounds, a new sensitivity to your tone, squeals and raspberries ahead, and true babble later. Copy the sound, add a word, and keep the sharp voice for adults.Try: Sound copycat
Week 14: sleep and play
Sleep reorganizing, drowsy but awake, day 100, drool, peekaboo, your song, and books.
Day 98Sleep is reorganizingWhat's actually changing in sleep around 4 months, why the '4-month sleep regression' isn't a research term, what longer stretches look like, and a three-step bedtime to start tonight.Try: Three-step bedtime
Day 99Drowsy but awake, and the pauseFrom 4 months the AAP suggests laying babies down drowsy, not asleep, and stepping up slowly before you pick up a fussing baby. What that is, what it isn't, and the step-up to try.Try: The step-up
Day 100One hundred daysA hundred days in. How growth works now, why slower gains from 3 months are normal in breastfed babies, feeds that get interrupted by the world, and a quiet corner to feed in.Try: Quiet-corner feeds
Day 101Drool, and the teething questionThe wet chin started weeks ago and teeth are months off for most babies. What teething does and doesn't cause, and something cool to gum, held by you.Try: Something cool to gum
Day 102Hidden things come backSometime after 4 months, babies start to grasp that a thing out of sight still exists. Peekaboo is the lesson, and it works on tired parents too.Try: Peekaboo
Day 103Your family songA song your baby hears from you, at the same moments every day, becomes a cue they recognize. Why the melody is social, and why the song is yours to pick.Try: Your family song
Day 104Fifteen weeks: booksThe AAP recommends shared reading from birth, and one trial found fewer behavior problems years later. A board book on your lap, and why the same three books forever is fine.Try: Board-book time
Week 15: the nights, and the floor
Sharing the nights, a rough patch, head shape, falls, the mouth, and seats.
Day 105Sharing the nightsParents' sleep bottoms out in the first 3 months and recovers slowly. The numbers, how to bank sleep, the drowsy-feed rules, and a written shift plan for tonight.Try: Tag-team nights
Day 106A rough patchNights that were getting better and suddenly aren't. Days bright, nights boring, the routine held steady, and the one thing exhaustion must never move.Try: The boring night
Day 107Head shape check-inFlat spots peak around 4 months and usually improve. The wet-hair check after the bath, the position swaps that help, and an hour of tummy time built from pieces.Try: An hour of tummy time, in pieces
Day 108Falls: no safe secondRolling can start without warning, and babies this age don't fear edges. Why the changing-table strap isn't enough, what to do if your baby fell, and the floor-change habit.Try: The floor-change habit
Day 109Everything goes in the mouthGrabbing on purpose means anything in reach ends up in the mouth. What's small enough to choke on, the cords and strings to clear, and a sweep of the play area at baby height.Try: The choke-size sweep
Day 110Walkers and seatsBaby walkers don't help babies walk and send thousands to hospitals; car seats are for the car; swings limit practice. Propped sitting on your lap instead, and the money you keep.Try: Sitting on your lap, propped
Day 111Sixteen weeksThe 4-month list, looked at gently one more time before the checkup: what most babies do by now, what a gap means, and why the answer is never to wait and see.Try: A milestone look, month four
Week 16 and four months
The checkup and shots, feeding cues, siblings, talk all day, pull to sit, the dangling toy, and a third of a year.
Day 112The 4-month checkupWhat today's visit covers, the second round of shots, how to make them easier (feed or suck, no medicine beforehand), what's normal after, and the screen that's about you.Try: Shot-day comfort, round two
Day 113Feeding cues at four monthsAn open mouth at the sight of the breast or bottle is a 4-month milestone and the clearest hunger cue you'll get. Distracted feeds, pulling off, and the formula-at-night question.Try: Watch for the open mouth
Day 114Big siblings as helpersBabies this age are intrigued by other children. How to give an older child a real job with the baby, the one rule that never bends, and what to keep off the floor.Try: The sibling song
Day 115Talk all dayReading from birth, the parentese voice, and copying sounds back with a word added. Why talk aimed at your baby is what counts, and the one screen that's allowed.Try: The narrated kitchen tour
Day 116Seventeen weeksHead steady when held is a 4-month milestone. A gentle pull-to-sit on the floor shows you what the neck can do now, and what it means if the head still lags.Try: Pull-to-sit, gently
Day 117The dangling toyBy 4 months many babies reach for and grasp what they see. A toy held within reach gives hands, eyes, and a would-be roller something to work for, with you holding the other end.Try: The dangling toy
Day 118Getting your attentionBy 4 months most babies look, move, or make sounds to get and keep your attention, and smile on their own to pull you in. A game that lets them call you first.Try: The attention game
Day 119What's nextWhat changed in 120 days, from two hours of crying to a chuckle, and what the 6-month list and the 4-month guide say is coming: laughs, raspberries, grabbing on purpose, rolling.Try: Four-month photo and letter
Day 120Four monthsThe 4-month list as a celebration, not a score: chuckles, a steady head, hands that grab, a voice that answers. A third of a year done, and the next guide.Try: The laugh collection