Week 4 at a glance
Week 4 marks the one-month milestone. The 1-month pediatrician checkup is the key event this week. Tummy time should be well established by now, and many parents notice baby becoming slightly more alert and interested in faces.
At 4 weeks, many babies have slightly longer awake periods — up to 60–75 minutes — and may briefly hold eye contact. Some babies begin to quiet when they hear familiar voices or music. The rooting, sucking, and Moro reflexes are still prominent.
This is a good week to introduce a brief tummy time session (with your full supervision) if you haven't already. Even 2–3 minutes on a firm surface helps build the neck and shoulder muscles babies need for every motor milestone ahead.
{callout("info", "Tummy time tip", "Place a rolled towel under baby's chest during tummy time to make it easier. Always supervise. If baby falls asleep, turn them onto their back immediately — tummy time is awake-only.")}Breastfed babies still feed 8–12 times per 24 hours. If feeds feel more efficient now — shorter sessions, strong swallowing — that's normal. Milk supply is usually better regulated by week 4, though many mothers still experience engorgement or leaking.
Formula-fed babies typically take 90–120 ml (3–4 oz) per feed, every 3–4 hours. Follow your baby's hunger cues rather than strict clock timing. Never force the last drops of a bottle.
Gas and reflux are common complaints this week. Frequent burping during and after feeds, keeping baby upright afterward, and gentle tummy massage can help. If symptoms are severe or baby isn't gaining weight, talk to your pediatrician.
Total sleep remains 14–17 hours. Wake windows are typically 45–75 minutes. Many parents notice the longest sleep stretch starts to shift slightly toward the night around weeks 4–6, but this is gradual and variable.
Safe sleep remains critical: firm flat surface, on their back, room temperature 18–20°C (64–68°F), no loose bedding, no sleep positioners. Our guide on newborn sleep by age covers what's normal week by week.
{callout("warning", "Sleep positioners", "Products marketed as 'sleep positioners' or 'anti-rollover cushions' are not safe for newborn sleep and have been linked to infant deaths. Babies should sleep only on a firm flat surface with no positioning devices.")}The 1-month checkup is the main health event this week. Your provider will confirm weight gain is on track and check for any early developmental concerns. Write your questions down before the appointment — new parent brain fog is real.
Wet nappies: still 6+ per day. Dirty nappies: breastfed babies may now go 1–3 days between stools; formula-fed babies typically still go daily. The umbilical cord stump should have fallen off by now — if it hasn't, mention it at your appointment.
⚠️ When to call your pediatrician
baby hasn't regained birth weight · fewer than 6 wet nappies per day · persistent vomiting (not just spitting up) that's forceful or greenish · yellow tinge to skin or eyes persisting past week 3 · any fever above 38°C (100.4°F)
Week 5 is often when colic peaks for many babies, bringing the most intense crying period. It's also when the first real social smiles may begin — a welcome milestone amid the exhaustion. See week 5 for what's ahead.
Your pediatrician will weigh and measure your baby, check their fontanelles, hips, eyes, and reflexes, and ask about feeding, sleep, and elimination patterns. It's a great time to bring any questions you've had since birth. Some practices give vaccines at this visit; others wait until 2 months.
Tummy time can begin from birth, but most families start by week 3–4. Begin with 2–3 minutes, 2–3 times a day on a firm flat surface while you supervise. Build gradually. Baby should never be left unsupervised during tummy time. It's the most effective way to build neck and upper body strength.
Yes — circadian rhythms take 6–12 weeks to develop. Most improvement happens between weeks 6–10. Consistent daytime light exposure and keeping nights quiet and dark helps accelerate this shift, but it's a biological process that can't be rushed significantly.
Spitting up after feeds is common in newborns as the lower oesophageal sphincter is immature. Keep baby upright for 20–30 minutes after feeds, try smaller more frequent feeds, and burp thoroughly. If baby arches in pain during feeds, cries excessively, or isn't gaining weight, discuss with your pediatrician as these may indicate reflux that needs treatment.
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1-Month-Old Development
Week-by-week newborn tracking, sleep logs, feeding tracker, and more.
Track your newborn →No credit card · No ads · Always free