← Baby, week by week

Week 4

One month in — and louder about it

A month already. Your baby is more alert and more vocal — including about their discontent. Crying is climbing towards its natural peak, so this week is partly about coping kit.

What a one-month-old can do

Your baby is likely fixing on faces, briefly following them side to side, startling at noises and calming to your voice. Their fists are mostly clenched and their movements still jerky — smoothness comes later.

In tummy time they may turn their head from side to side and make the first tiny attempts to lift it. Little and often is still the recipe.

Every baby's timetable is its own. These are ranges, not deadlines — health visitors and paediatricians look at the overall picture, not a single tick-box.

Crying: the hard-work phase

Crying typically keeps building from now towards a peak around six to eight weeks — at the peak, a couple of hours a day is average, and some perfectly healthy babies do more. Late afternoon and evening are prime time.

About 1 in 5 babies cry so much and so inconsolably that it gets called colic. It happens across breastfed and formula-fed babies alike, it isn't caused by anything you did, and it fades — usually well before 5 months.

Soothing is trial and error: holding close or in a sling, gentle motion, sucking (breast, clean finger or a dummy if you use one), a warm bath, white noise, or stepping outside. What worked yesterday may not work today; that's babies.

Sleep at one month

Total sleep is still spread around the clock, though some babies start to give one slightly longer stretch — often, unhelpfully, starting at 7pm while you're awake.

Keep following safer sleep for every sleep, naps included: back to sleep, clear flat cot, same room as you. If you use blankets, tuck them below shoulder height with baby's feet at the foot of the cot.

Dummies divide opinion, and honestly the evidence is mixed on some points — but if you use one for sleep, the Lullaby Trust suggests offering it consistently, and if you're breastfeeding, many families wait until feeding is well established.

And you

The one-month mark can feel like hitting a wall: the adrenaline is gone, the visitors have stopped, and the nights are still relentless. Feeling flat or trapped in the loop of feed–wind–change is common and worth saying out loud.

If low mood, hopelessness, constant anxiety or not enjoying anything has lasted more than a couple of weeks, that could be postnatal depression — it affects around 1 in 10 mums, and dads and partners get it too. Your GP and health visitor genuinely want to hear about it.

Build the crying-peak survival plan now: who you can call, who can take a shift, and the reminder on the fridge that it's OK to put the baby down safely and step away.

Feeding at this stage

Pick how you're feeding — we'll remember for next time. Every one of these is a good way to feed a baby.

Breastfeeding

  • Feeds may be getting slightly more efficient — some babies now finish in 15–20 minutes what once took 45, while others still linger; both are fine.
  • Evening cluster feeding often continues through the crying-peak weeks — feeding to soothe is allowed, and you cannot overfeed a breastfed baby.
  • If you're thinking about introducing an occasional bottle of expressed milk, somewhere around now — once feeding feels established — is when many families find it works smoothly.

The full breastfeeding guide →

Breast + expressed

  • If you're combining breast and expressed bottles, keeping most feeds at the breast (or matching removed feeds with a pump) keeps supply steady.
  • Evening expressing can be dispiriting — output is naturally lower then; mornings remain the generous slot.
  • Let someone else give an expressed bottle occasionally — a fed baby, a rested parent and a bonding partner is a good trade all round.

The full breast + expressed guide →

Breast + formula

  • Many combination-feeding families settle into a pattern around now — for example, breastfeeds by day and one formula feed in the evening; there's no single right recipe.
  • If your baby is fussier at the breast in the evening, that's usually the normal evening fussies, not your milk — formula-fed babies have the same witching hour.
  • Keep bottle feeds paced so your baby can move happily between breast and bottle.

The full breast + formula guide →

Formula

  • Appetite still varies day to day — responsive feeding (offering when hungry, stopping when done) beats chasing a fixed number of millilitres.
  • During evening fussiness, resist the urge to keep offering more milk as the only tool — motion, sucking, a bath and being held work for formula-fed babies too.
  • If your baby seems uncomfortable after feeds, check teat flow and pacing before blaming the formula — and talk to your health visitor before switching brands, as frequent switches make it harder to spot what helps.

The full formula guide →

Totally normal (even when it doesn't feel it)

  • Crying more than ever, especially in the evening — the normal crying curve is still climbing and peaks around 6–8 weeks.
  • Inconsolable patches where nothing works — some crying at this age has no findable cause, even for professionals.
  • No smiles yet — many babies smile for the first time around 5 to 8 weeks, and a bit later is still normal.
  • Jerky arm and leg movements and trembling chins — smooth movement is a work in progress.
  • A flat-ish patch developing on the back of the head — common with back-sleeping; tummy time and varying head position while awake help, and it usually rounds out.
  • Cradle cap — greasy yellow scales on the scalp — looks dramatic and bothers babies not at all.
  • Your baby feeding to sleep — at this age it's biology, not a bad habit.

Worth checking

You know your baby best — if any of these ring true, or something just feels off, it's always OK to ask.

  • Fever of 38°C (100.4°F) or above — same-day advice, every time, at this age: call your GP or NHS 111 (UK); in the US, your pediatrician.
  • Crying that is constant and can't be soothed at all for hours, especially with fever, vomiting or a swollen tummy — call your GP or 111; in the US, your pediatrician.
  • A baby who has stopped feeding, or wet nappies dropping noticeably — call your health visitor or GP; in the US, your pediatrician.
  • Breathing that looks like hard work — grunting with each breath, ribs sucking in, unusually fast — call 999 (UK) or 911 (US).
  • A bulging or noticeably sunken soft spot (fontanelle) when your baby is calm and upright — call your GP urgently or 111; in the US, your pediatrician.
  • A non-blanching rash, blue or grey lips, floppiness or a seizure — call 999 (UK) or 911 (US).
  • If you ever feel you might hurt your baby or yourself — put baby somewhere safe and call 999 (UK) or 911/988 (US), or Samaritans on 116 123 (UK). Help is real and nobody will judge you for asking.