3 Week Old Baby Development

Learn everything you need to know about your 3 week old baby. Track important developments and milestones such as talking, walking, growth, memory & more.

Published on June 7, 2017

Mom smiling at newborn at hospital — Photo: Getty

Your Growing Baby

Gaining Strength

Your baby is getting stronger by the day. Even though her head is still wobbly and needs to be supported when you hold her, by now she might be able to lift it up for a few seconds or even turn it from side to side. That milestone goes hand in hand with rapidly maturing vision, since she's developing an eagerness to check out the world around her -- particularly her parents. Young babies adore looking at faces, so give her plenty of up-close time so she can gaze at you. Grin or stick out your tongue and she might even attempt to copy you. Bold-pattern toys -- books, balls, rattles with black-and-white stripes, bull's-eyes, or checkerboards -- also get her attention these days and boost her vision.

Playtime and cuddle time still take a back burner to nap time, though -- between 2 and 3 weeks old, your baby's still sleeping a ton. Most 3-week-olds doze for 16-18 hours a day, usually in three- to four-hour stretches. After that, her rumbling tummy will wake her and she'll ring the dinner bell by crying for you. Don't worry if her sleep-wake schedule is all over the map for now. Babies are still learning to differentiate between night and day, and they don't usually settle into any semblance of a regular schedule until 6 weeks of age or beyond. For now, stay flexible. Car seats, swings, slings, and bouncy seats all make stellar daytime sleep spots. Even better? Napping when your baby naps. (The to-do list can wait.)

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Health and Safety Info

Bathtime Must-Knows

Bathtime! Once what's left of your baby's umbilical cord falls off, she's ready for her first real tub bath. If the idea of sudsing and lifting that slippery, wiggly little body makes you nervous, invest in a baby bath tub with a sling/hammock for newborns or a sponge bath insert to cradle your baby. For a newborn, a clean kitchen sink also makes a terrific (and free!) bathing spot, too; just layer a few towels beneath her for cushioning and traction. If you can, avoid your regular bath tub for now. A smaller space will keep your little one from sloshing around like a teeny fish in a giant pond -- and help you keep your hands on her.

Before you get started, grab all your supplies and make sure they're within arm's reach, since you shouldn't take your hand off her for even a second once she's in there. The basics include baby wash, a mini washcloth, a small cup to rinse her head and body, a baby hairbrush, and a towel to keep her cozy when it's all over. Take special care to make sure the water isn't too hot. Test for a lukewarm feel by dribbling some water on your wrist, or use a tub thermometer, aiming for 95 to 100 degrees, per the American Academy of Pediatrics. Fill the tub about 3 or 4 inches deep, then slide your baby in. Soap her up with the washcloth, and gently massage her scalp with the hairbrush. Rinse with a few cups of warm water, then wrap her up in a towel. All clean!

Must-Knows

Tricks to Calm Baby

In the first few weeks, the older your little one gets, the more she'll cry, peaking around 6 weeks old. While fussing and wailing is totally normal for babies -- think of it as your little one's only way of telling you how she feels -- it can be super stressful for you, particularly if you're not sure how to soothe her. In a quiet moment, make a master list of potential solutions, such as offering a pacifier, massaging her belly or back, swaddling her, popping her in the baby swing, changing her diaper, checking for clothing irritations, or taking her for a car ride. When your little one starts up again, you'll have an arsenal of antiwail weapons at your disposal.

But sometimes babies just need to cry as a way to vent their out-of-control emotions when they're feeling overstimulated or overtired; it might actually help them calm themselves down. If your baby isn't hungry, doesn't have a dirty diaper, and doesn't have any other clear reason why she'd be so cranky, it's perfectly fine to let her howl it out for a bit. Place her in her crib or bouncy seat and walk away for a 10-minute Mom time-out. A few deep breaths, a dip into a book, or an SOS phone call to another mom pal will clear your head and help you deal with the fussing without melting down yourself. Bonus: You're actually doing her a favor by allowing her the chance to self-soothe, a valuable skill for your baby to learn.

Of course, it won't "spoil" the baby if you prefer to hold her until she calms down, either. Just remember that if the crying is ongoing and overwhelming -- and it's stressing you out -- give your pediatrician a call for help.