3-Week-Old Baby Milestones

Compared to life in the womb, the world is quite big (and airy!) to your little baby. But, by 3 weeks, you’re probably itching to expand your own surroundings. For most families, leaving the house with the baby is a process of gradually expanding your comfort zone—learning to use the carrier or stroller, first with walks in the neighborhood, then onto bigger adventures.

Your baby’s immune system is pretty weak for the first 3 months (and vaccines don’t start until 2 months), so you’ll want to play it safe with potential germ exposure. Going out of the house: Keep your distance—meeting friends outside is best. And remember, germs are “sticky,” so wash or sanitize your hands frequently…and resist the temptation to pass your baby around. This is an important time to be overprotective. (See more germ hacks for protecting your baby) 

At home: People are often contagious with illnesses a few days before they feel sick. So, only allow your very closest friends/family to visit during these first months. Ask them if they have been around anyone who is ill. Put a stack of clean t-shirts by the front door and put a sign on the door reminding people that—as soon as they enter…before they give you a hug—they should wash hands and put a clean t-shirt on over their clothing.

3-Week-Old Baby Sleep

By 3 weeks, your little one is really waking up to the world! You’re getting the chance to gaze into your lovebug’s eyes a bit more often because when they are awake, they are really awake! All that means more sweet coos and loud cries…or a combination of the two.

As parents, any amount of baby tears can seem like too much. (You want them to be happy!) Remember, though, crying is one of your baby’s best tools for communicating a need like hunger, discomfort, or tiredness. 

During these first weeks, when your baby cries, it’s always fine to offer a feeding (even if you just fed your baby 30 minutes before). But, if you’re not quite ready, or your baby resists the nipple, give the 5 S’s a try. 

Are you thinking, “I’m trying, but it’s not working yet?” Precision, practice, and vigor are key at this point—as is figuring out your baby’s preferred mix of the S’s. (Doing the steps correctly is important. Baby calming is like tying your shoelaces, it can take a little practice. If your baby doesn’t seem to be responding…don’t give up. Instead, watch The Happiest Baby video to master the skills.)

Last point, infants don’t need rigid schedules, but even little babies do best with a bit of predictability and routine. Over the coming months, your baby’s brain will begin to differentiate between day and night. That’s where a little “evening/bedtime routine” can help. Each evening, turning on the white noise, turning down the lights, doing a little warm oil massage, darkening the room, and giving a feeding helps babies learn what’s expected of them. “Okay, I get it. It’s time to sleep.” By getting those circadian rhythms on track, your baby will come to be a more eager, willing participant at bedtime. 

Keeping an all-night routine helps, too. We recommend swaddling for the first couple of months and using white noise for all naps/nights for the first several years. Or use SNOO (which offers both + womb-like rocking). At this early age, SNOO will give your baby hours and hours of calming, healthful rhythms and will give you peace of mind that they’re safely secured - to prevent accidental rolling. But, SNOO will likely just add about an extra 20 to 30 minutes to each sleep cycle. That’s because babies need lots of feedings. By 1-2 months, you can expect to see 4 and even 5 hour stretches.

Your 3-Week-Old Baby’s Development 

Hitting the (Play) Gym

Tummy time is more than a cute phrase—it’s an important way to help your baby develop their muscles and gross motor skills! Your baby can start practicing a bit of neck strengthening exercise in another week or two (just a couple of minutes at a time). But, as you might have already noticed, laying tummy down on a playmat and lifting that heavy little brainy head is not every baby’s idea of fun. 

If your baby’s fusses when you do tummy time, don’t throw in the towel. Instead, try holding your baby upright in your arms, supporting the head, but letting it tilt a little forward and then a little back to give a bit of practice for the neck muscles. By 3 to 4 weeks, your baby should be able to raise their head for a few seconds and perhaps turn it from side to side. 

If you do have a tummy time fan, add a book or toy that has a black-and-white pattern or red color to give them something interesting to look at. Babies are captivated by high-contrast patterns.

Feeding Your 3-Week-Old Baby

How much should a 3-week-old baby eat?

A 3-week-old baby eats about 2 to 3 ounces of milk about every 2 to 3 hours. For breastfed babies, count on nursing about eight to 12 times in a 24-hour period.

Your 3-Week-Old Baby’s Health

Don’t Be Alarmed…

When you looked ahead to parenthood, you were probably prepared for some sleepless nights, lots of feeding and the sweet cuddles. As you know by now, life with a baby can be a little more complicated than that.  

• With babies, what goes down can sometimes come back up in the form of spit-up. Common among babies for the first few months, you can help cut down on the spit-up by burping your baby and keeping them upright after feeding for a few minutes.
• Flat Head Syndrome (which is like it sounds) can happen when your baby only rests with their head on one side. You can help avoid this by putting them to sleep in their crib or bassinet with their head facing in different directions—like to the left side of the crib one time and to the right side of the crib the next. (But you should not use pillows or cushions in the bed.)

3-Week-Old Baby Red Skin

Newborns are famous for their sweet smelling and irresistibly soft skin…that comes with the side-effect of being super sensitive. If your little one is experiencing skin flare-ups, here’s what to know:

• Red, scaly patches on the body (eczema) can be related to overly dry skin or food allergies (even to something in your diet that comes through the breastmilk). These patches are most common in the folds (neck, behind ears, inside elbows or knees, and the diaper area). If you think you might be seeing this, check in with your doctor.
• You probably thought that acne would hold-off until the teenage years, but babies also experience some big hormonal shifts after birth.  But don’t worry…cheek pimples should clear up automatically—with no treatment or scrubbing—by 6 weeks.

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Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.