5 Week Old Baby: First Coos, Early Smiles and What to Expect

Your Baby at 5 Weeks Old

A 5 week old baby is more alert, may begin cooing, and is building toward the first social smile — a milestone the Canadian Paediatric Society places by the end of 3 months. Feeds run on cue, around 8 to 12 times in 24 hours, and a 5 week old may sleep up to 18 hours a day, for 3 to 4 hours at a time. Normal newborn crying peaks around 3 to 12 weeks.

Your 5 week old baby is becoming more sociable — longer alert windows, more eye contact, and the first soft coos. After weeks of one-way effort, it can start to feel like your baby is saying hello.

This guide covers what to expect this week: the first coos and the smiles on the way, how feeding and sleep are shaping up, why crying often peaks around now, and how to look after yourself through it.

Your Life This Week: The Parent Experience

Five weeks in, you may be running on very little sleep just as your baby's crying is at its most intense — and then a first coo or near-smile lands and softens everything. Both are true at once: it's depleting and it's tender. That mix is normal.

A gentle daily rhythm still helps: feed, an alert window, wind-down, sleep. Use your baby's new alert times for face-to-face play and their sleepier stretches for your own rest. Keep accepting help.

Peak crying weeks are hard on a tired parent, and feeling frustrated is normal. The "baby blues" affect up to 80% of new mothers and usually ease within a few weeks, the Canadian Paediatric Society notes. If low mood, anxiety or a sense of disconnection lingers or feels heavier than that, it may be postpartum depression, which affects about 13% of new mothers, and as many as 10% of fathers. It is treatable — please tell your doctor or public health nurse.

Feeding Your 5 Week Old Baby

A 5 week old baby feeds on cue. The Canadian Paediatric Society advises feeding on demand and notes that in these early weeks, breastfed babies feed around 8 to 12 times over a 24-hour period. For formula, follow the feeding chart on your formula's packaging and let your baby's cues guide the amount. The CPS signs of feeding well still apply: six or more wet diapers a day, soft yellow stools, a content baby, and steady weight gain.

Some cluster feeding and fussiness may still be around, often at its most intense during the normal peak crying period of 3 to 12 weeks. This is normal and temporary, and it doesn't mean your baby needs a bigger bottle every feed. Offer calm, paced feeds and comfort, and let your baby lead the pace.

Whether you breastfeed, formula feed or combine the two, your baby's fast brain and vision development runs on the right nutrients — including the fat DHA, along with iron and vitamin D. If breastfeeding isn't an option, the Canadian Paediatric Society advises a store-bought, iron-fortified, cow-milk-based infant formula for the first 12 months — fortified to provide these.

A note on formula this week. As your baby grows more alert, feeds become calmer, more interactive moments — a chance for eye contact and connection. MOF's organic Stage 1 formulas, such as HiPP Dutch Stage 1, are iron-fortified and suitable from birth through 6 months, providing the DHA, iron and vitamin D that support your baby's rapid brain and vision development. Formula is a good choice whenever it's the right one for your family.

Sleep at 5 Weeks: What's Normal & How to Help

A 5 week old baby may sleep as much as 18 hours a day, for 3 to 4 hours at a time, according to the Canadian Paediatric Society — and waking to feed at night is normal and healthy. There's no settled, predictable night sleep yet, and that's expected at this age.

This is developmentally on track. The Canadian Paediatric Society notes that sleep habits become more predictable sometime after 3 months, so from here you may gradually see the first hints of longer stretches. No method will force settled nights before your baby's body is ready.

Keep reinforcing day and night: bright, active days and calm, dim, quiet nights. Put your baby down drowsy but awake when you can, and protect your own rest wherever possible.

Safe sleep reminder: always place your baby on their back for every sleep, on a firm flat mattress with a tightly fitted sheet and no loose, soft items, in a crib, cradle or bassinet in your room for the first 6 months. The Canadian Paediatric Society advises this lowers the risk of SIDS.