Month-by-Month Baby Development (0–6 Months)

"My neighbor's baby has started rolling over, and mine is still just looking around!"—stop, no comparing. Every baby develops on their own timeline, and the range we call "normal" is far wider than people think. In fact, experts recently redefined the milestones—based on "the age by which three-quarters of children can do it"—so as not to worry parents needlessly.

This guide gives you two things: a map of what you can expect each month, and a short list of the signs that genuinely warrant checking in with your doctor.

• Looks at your face and starts to follow you with their eyes; startles at loud sounds.
• The big moment: around 6–8 weeks, the first SOCIAL smile—not gas, but truly for you!
• Lifts their head briefly while on their tummy; discovers bringing a hand to their mouth.
• Your job: plenty of eye contact, talking, and tummy time (see below).

• The cooing concerts begin ("oooh," "aaah"); when you talk, they make sounds as if answering back.
• Now holds their head up without support; starts reaching for objects and trying to grab a toy.
• Spontaneous, joyful smiles and the first giggles are the gift of this stage.
• Your job: back-and-forth "conversation" (when they make a sound, you answer), safe toys they can reach for.

• Rolling time: from tummy to back, then from back to tummy (on experts' updated timeline, rolling is a 6-month milestone—a baby who isn't rolling at 4 months is NOT behind).
• Attempts at sitting with support; grabbing everything and bringing it to the mouth (that's how exploring is done!).
• Belly laughs, syllable sounds ("ba," "da"), and fascination with the baby in the mirror.
• Your job: a supervised play area on the floor, and getting your home baby-proofed now.

• What: face-down play while your baby is AWAKE and you're watching. It strengthens the neck and shoulder muscles, prevents the back of the head from flattening, and is a rehearsal for rolling over.
• When: starting in the first days; begin with 1–2 minutes a few times a day, working up to a total of 15–30 minutes by 3–4 months.
• Does your baby hate it? Start by laying them on your chest, put a colorful toy or a mirror on the floor, and keep sessions short but frequent.
• Golden rule: tummy time is only for PLAY; sleep is always on the back.

The following is a "mention it at a checkup" list, not a "panic" list—early evaluation does no harm and can do a lot of good:

• By the end of month 2: no reaction at all to loud sounds, not following faces, no social smile.
• By the end of month 4: can't hold their head up, doesn't smile at people, doesn't coo at all, doesn't reach for objects.
• By the end of month 6: not trying to roll over at all, head control still weak, no vocal responses or laughter, uninterested in their surroundings.
• At any age: losing a skill they had gained—this should always be evaluated.

This guide is general information compiled from reliable health sources; your baby's developmental progress varies from person to person, and nothing here is a substitute for an examination. Always make your decisions under the guidance of your doctor and family physician; whenever you're unsure, consult them first.