9-Month-Old Baby Development

Congratulations! If you have a nine-month-old, your baby has been on the outside at least as long as they were on the inside. Nine month olds are wonderful—they’re so close to being toddlers, while still being cuddly, delightful babies. And this is the time when you’ll start to see even more of your baby’s personality emerge, as they develop new skills that allow them to communicate and express preferences even more easily than they have before. There’s a wide range of typical development for babies this age, so in this blog post we’ll talk a bit about what to expect from your nine month old.

Sleep: your nine-month-old is probably taking two naps a day (maybe a third quick nap, if they really need it) of about an hour or two each. They’re probably staying awake two to three hours between sleep episodes. Night sleep has hopefully improved from when they were younger, and baby is likely sleeping between eleven and twelve hours at night. When considering naps, that means baby’s probably getting a total of 13-16 hours per 24 hour period. Some nine month olds sleep all night without waking to eat, while others still need to eat once or twice in the night. Consult with your pediatrician about nighttime feeding and your child’s sleep if you have questions or concerns.

Eating: nine month olds still largely rely on breast milk or formula for the bulk of their calories, though they can eat lots of foods at this age, even if they don’t have teeth. This age of baby is starting to get good at picking up finger foods with a pincer grasp, feeding themselves, and using their jaws to mash up soft foods like cooked carrots, bananas, and beans. Baby can likely sit upright in a high chair pulled up to the family table during meal times.

Motor milestones at nine months old include: sitting more confidently and for long periods of time, crawling, banging things together, and shaking things. Some nine month olds may also start to pull themselves up to a standing position by holding onto the couch or a low table and appreciate toys they can support themselves with and push while standing. Very early walkers take steps at nine months old. It’s important to mention again that there is a wide range of normal here, so if your baby isn’t doing these things yet, it’s probably okay. You can support baby’s motor development by giving them lots of time to play and move in a safe place and by dressing them in comfortable clothes that are easy to move in. It’s always okay to check in with your baby’s care provider if you’re worried.

In terms of social behavior, you’re likely to see your nine month old babbling (saying lots of syllables over and over, like “bababababa” and “dadadadada”), imitating your speech sounds, responding to their name, and showing some understanding of simple commands (“come see mama”). Nine month olds also often develop separation anxiety, where they get sad and clingy when a loved one leaves and may show fear of new people. They enjoy games like peek-a-boo and pat-a-cake and might have a favorite toy. They can make sounds and sometimes point to indicate preferences in food or activities.

Playing with your baby is probably just getting more fun, as baby can interact and do much more. If your baby can crawl, try crawling away from them around a corner and then peek out at them. They’ll likely grin and crawl straight toward you to find you. This game can last for hours with a nine month old, as it plays to their strengths in motor and social development. Babies also like rhythm instruments—such as tambourines and maracas—at this age. It’s also really fun to read books with baby, as their vision is just getting better and they can even sometimes help by turning the pages. Reading books together also helps with baby’s language development. And while playing together is fun, you don’t have to feel the need to entertain your baby all the time. Many nine month olds are perfectly content to explore and play in a room with you nearby.

Abby Olena
Dr. Abby Olena has a PhD in Biological Sciences from Vanderbilt University. She lives with her husband and children in North Carolina, where she writes about science and parenting, produces a conversational podcast, and teaches prenatal yoga.

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