Three-Week-Old Baby: Feeding and Sleeping Expectations

By the time your baby is three weeks old, you two are really getting to know each other. You might be starting to have a good sense of their cues for feeding and sleeping. Or maybe you haven’t even thought about this yet and are just trying to make it to the next nap! Whether you’re the former or the latter, that’s okay!

Since every baby is different and goes through unique growth spurts and stages, your baby’s cues are the best way to know what they need. As you and your little one learn more about each other, this will become easier, so don’t worry! Just being aware that babies have these cues makes you one step ahead of the game.

Your Three-Week-Old Baby and Feeding

For breastfeeding, your three-week-old is still nursing anywhere from eight to 12 times per 24 hours.¹ You should offer both breasts at every feeding session, alternating which one you start with. Your baby might not want both each time, and that’s okay as long as they’re growing and developing well.²

Bottle-fed babies usually take in about 3-4 ounces every three to four hours, for a total of about 20-32 ounces per day.^3,4 It’s still a good idea to wake them during the day to get these feeds in. This allows them to sleep as long as they will go at night.⁴

Pay Attention to Hunger Cues

Aim to feed your baby on demand, meaning whenever they show signs of hunger.⁵ Stop feeding them when they show signs that they’re full.⁶ Remember, all the ranges you read are a guide because every baby is different. So, now is a great time to start identifying your baby’s early signs of hunger. Once the later signs begin to emerge, it can be more difficult for baby to feed.⁷

Here are some early hunger cues:^1,6,7,8,9,10

• Putting their hands to their mouth
• Turning their head toward the breast or bottle
• Puckering, smacking, or licking their lips
• Having clenched hands
• Sucking on their hands, lips, toes, clothes, toys, and fingers
• Opening and closing their mouth
• Sticking their tongue out
• Moving their head from side to side
• Being more alert

The following are later hunger cues:^5,6,8

• Moving their head frantically from side to side
• Fussing
• Crying

How To Know If Your Baby Is Full

It can be hard to tell sometimes if your newborn baby is full. Babies love to suck, so it can feel like they’re always hungry and would happily keep sucking away. But you should start looking for your baby’s cues that they’re full. Sometimes these cues are subtle, sometimes not so subtle. Here are some signs that your baby might be full:^6,8,9,10

• Pushing the nipple away
• Relaxation of the facial muscles so the nipple slips out of the mouth
• Relaxation of hand muscles so the fists open up
• Closing their mouth when food is offered
• Turning their head away from food
• Falling asleep

Your Three-Week-Old Baby and Sleep

Your three-week-old baby still needs a lot of sleep, about 14-18 hours a day.⁴ Unfortunately, they still have their days and nights mixed up.¹¹ Often, in the late afternoon and evening hours, your baby (who was pretty calm all day) can start to be fussy. We typically call this the witching hour.¹² It usually begins when baby is about three weeks old, peaks around six weeks, and then improves around three months.^12,13 Gas is also very prominent around this time and often gets blamed for the fussiness. One of the things I find often contributes to this witching hour is a cycle of overtiredness.¹²

Baby Is More Alert Now But Still Needs Sleep

At three weeks old, your baby will be more alert when awake. New parents often think their baby is supposed to be awake for very long stretches. So, baby is awake and alert until they start crying, and that’s when the parent thinks, “Okay, my baby must need to eat or sleep now.” However, crying is a later sign of both hunger and tiredness.^5,8,14

There are some things your baby might do much earlier to show they’re getting sleepy, and these are what you should be looking for. They’re different for every baby, so study your little one closely.¹⁵ This isn’t a big ask, right? After all, you love staring at that cute little newborn’s face! But use your time wisely, and see what your baby does before the crying. If you pick up on this and put them down for a nap at the first sign, it’s so much easier — trust me! It’s much harder to get an overtired baby to fall asleep.

Pay Attention to Sleep Cues

So, pay close attention to your baby’s earlier sleepy cues, and try not to miss the boat on this! The good news is that if you miss the boat today, you’ll get another chance tomorrow and the day after, too. Newborns aren’t usually awake for that long before showing signs of tiredness. The amount of time they’re awake is often referred to as the “wake window.”¹⁵ This can vary but is usually around 30-60 minutes at this age.

Here are some tired cues your baby might show:^{14,15,16,17,18}

• Your baby might stare blankly into space or yawn.
• Tired eyes might look like red eyelids or eyelids half-closed. Their eyes can also seem heavy, watery, fluttery, or slow to blink. They might even cover their eyes with their hands or rub them. Also, they might have difficulty focusing or go cross-eyed.
• They might turn away to the side.
• They might become quieter, slower, or less focused.
• Your baby might have a weak suck, close their fists, make jerky movements with their arms and legs, or start arching backward.
• They might frown or look worried.
• They might start sucking on their fingers or pulling on their ears.
• FINALLY, later on, your baby will get cranky, fussy, and start crying.

Don’t Worry About Sleeping Habits Yet

Your three-week-old will still need to sleep and feed often. Naps can be as short as 15-20 minutes. Sorry, mama, but it still counts if this is all they’ve slept! Although you can try to get your baby back down right away if their nap was that short, babies this age rarely do more than one or two long stretches of sleep in a day.¹⁹ And “long” is often only around four hours. It can be longer and more consistent, but if it is, I recommend you don’t tell anyone! That’s a surefire way to make it stop or to get another new mom very angry and jealous.

Three weeks old is way too early to establish good or bad sleeping habits, so please don’t worry about that yet. Your newborn is still in survival mode, just like new parents often are, too! Do whatever you need to get your baby to sleep. Of course, always remember to follow safe sleep guidelines once your baby is asleep. Here are some things you can try:^4,20,21,22

• Nursing or feeding your baby to sleep
• Rocking or bouncing them in your arms
• Swaddling
• Using a pacifier
• Putting up blackout curtains
• Playing white noise
• Singing
• Using a baby carrier
• Using a stroller (read here for more baby sleep products 0 to 6 months)

Your baby was curled up nice and cozy for about 10 months. It was also dark, warm, and soothing in the womb. Adjusting to this new world takes some time. Sometimes that’s all your little one needs: time to adjust. In the meantime, enjoy those newborn snuggles!