21 Week Old Baby Development

Learn everything you need to know about your 21 week old baby. Track important developments and milestones such as talking, walking, growth, memory & more.

By Parents Editors

Published on June 12, 2017

Your Growing Baby

On the Way to Crawling

Your baby's rollovers are growing more sophisticated, and he's likely able to flip himself in both directions. Your baby also might be creeping or scooting around on his belly, although he's probably not ready for real hands-and-knees crawling yet. (Between 7 and 10 months is more typical for that step, if it happens at all.) Some babies skip crawling altogether and transition directly to standing up and cruising, so don't be alarmed if he's not showing any signs of creeping or crawling yet.

Learning to Crawl

Chatty Baby

You might notice your baby's chit-chat is changing now too. In addition to the usual baby babble, he might experiment with intonation, pitch, and volume, like a singer recording his very first album ("Babbling: The Early Years"). By now, your baby should know his name and will turn toward you when he hears you call it.

Age-by-Age Guide to Your Child's Language Skills

Baby's Favorite Foods

Continuing to provide a variety of solid foods in addition to breast milk or formula (which are still your baby's primo nutrition source) will help your child develop normally. As your baby's palate expands, you might notice that he's drinking less than usual. It's normal for babies to ease back a bit on milk or formula as they develop more of an interest in solids. Odds are he loves sweet foods—applesauce, mashed bananas, and sweet potatoes—the best. That's because babies have more taste buds for sweetness than for other flavors.

Solid Foods: How Much & When

Health and Safety Info

Teething Soothers

Has your baby cut his first tooth yet? Strangely enough, your baby's teeth began forming in the early months of your pregnancy, but they won't actually show up until baby's 5 or 6 months old, or sometimes much later.

Even if he's still all gums, your baby could be teething; the process actually begins one to three months before the first teeth actually show up. Symptoms include major drooling, an occasional cough (triggered by excessive saliva), chin rash (saliva again), swelling of the gums, and fussiness while feeding. Your baby will want to chew everything he can get his mouth on, so be sure to have safe and soothing stuff on hand: teething toys, chilled rubber teething rings, or a cold, clean baby washcloth.

Before the first teeth break through the gums, you should start implementing some good dental hygiene habits. Keep baby's gums (and any tiny teeth) clean by wiping them with a damp cloth or using a baby toothbrush with toothpaste designed for infants, which he can swallow without problems. It'll clean the remnants of food and milk out of his mouth, and it'll get him used to the feel of having his teeth cleaned. That'll mean fewer struggles when teeth come in and you need to get more serious about brushing later on.

Must-Knows

Stop the Drool

Is your teething baby leaving a trail of drool wherever he goes—including on the shoulder of every shirt you own? Is he a chronic spitter who requires a shirt change—for you and for him—whenever he eats? Keeping the two of you clean and neat can be a major challenge, particularly once your little one starts eating (and throwing) solids. Without your own force field, is there any way to avoid being covered in your baby's spills, splats, and spits?

Our advice: Stock up on bibs for your baby and burp cloths for your shoulder. When you're at home, go for the gusto with strategically draped small blankets instead, or keep a few old T-shirts on hand to slip over your shirt. Some working moms prevent last-minute outfit emergencies—and astronomical dry cleaning bills—by waiting until two minutes before they have to walk out the door before they slip into their work clothes each morning. If you're a stay-at-home mom, you might be wise to develop a wardrobe of wash-and-wear shirts and pants.

On the occasion when you do get hit with a stain, pretreat with a stain removal spray before a sweet potato spill or formula spot has time to set. Otherwise, just consider a few clothing casualties one of the costs of motherhood.

Shop for Bibs