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Your 9-Week-Old Baby: Development & Growth

Table of Contents

9-Week-Old Baby

Table of Contents

Breast Pumps, bedtime routines, and your baby’s developing sensory system. Let’s also talk about sex! Week 9 is where you start to get a hang of things!

Your baby's ninth week after birth

When compared to anything before, 9-Week-Old Baby growth spurt will be quite substantial. Considering how they have completely developed their hearing, your baby might start noticing the subtle differences between different sounds. They will react to these sounds, for instance, try playing their favorite song and they will kick their legs animatedly. During this time, your little one might also experiment with their grip making it the best time to give them a rattle. Your baby starts developing better hand-eye coordination. Although their coordination is still in the initial stages, it’s better than before.

Your 9-week-old baby's development and physical growth

Here’s what’s happening with your baby and in their body in terms of their physical development in the ninth week after birth.

1. Your baby’s weight:

  • n average, a 9-week-old baby should weigh 11.3 pounds, if you have a baby girl. Whereas the average weight of a baby boy should be around 12.3 pounds.
  • Moreover, a 9-week old baby will gain around a kilo to a kilo in weight. This is half more than what it was since their birth. You can look forward to this healthy milestone.

2. Your baby’s sleep:

  • By the ninth week, your baby (and you) might be able to sleep for six or more hours during the night. However, you can expect some relapse. 
  • Try to help your little one by keeping up a bedtime routine. Every night put your little one to sleep at the same time and stick to the same pre-bed activities.
  • The pre-bed activities can include a warm bath and a bedtime story or lullaby before you tuck them in. 
  • Your baby is also better equipped to soothe themselves back to sleep. 
  • Usually, when babies are this old, they get used to those dummy nipples. If it falls off during their nap, they might fail to sleep properly. 
  • Start weaning them gradually, if your baby is already used to it as it is beneficial for the long run. 
  • Keep working at bettering your little one’s bedtime routine and habit. Eventually, you’ll get a through-the-night sleep.

3. Your baby’s diet:

  • A nine-week-old baby needs more feeding than a newborn. 
  • Due to their continuous growth spurts, they’ll be feeding more than usual. 
  • During this time, usually, your baby would need about 5 to 6 feeds over 24 hours. 
  • They won’t overeat at this age, so simply follow their lead when they are hungry.
  • A good guideline that you can follow is to feed them 150 to 200ml per kilo of their weight. You can’t measure if you’re breastfeeding them and not expressing, so just continue feeding according to their reaction. 
  • Just in case, offer them the second breast even after they seem full with the first one.

Your 9-week-old baby's reflexes

  • As your little one is developing more physical control, their newborn reactions (such as the Moro or startle reflex) will eventually start to fade. 
  • During the ninth week, you can expect some new abilities. 
  • Your little one might start shimmying around on their belly and even wiggle off their blanket during tummy time. 
  • Although, you can’t expect a full rollover as of yet (which is a milestone that will most likely happen between 4 to 6 months), some babies will start rolling from their back onto their side. 
  • Also, there’s no need to worry if your little one appears to be moving less. 
  • It could mean that your baby’s more fine-tuned movements are less noticeable. 
  • Your baby could also be working on another, less-physical milestone at the moment.

Your 9-week-old baby's health

Here are some things you should focus on once your little one reaches the ninth week:

Your baby’s cries:

Your little one’s tear glands will be fully developed by now so expect to see some waterworks. If you don’t it could mean that your baby has a blocked tear duct. After your baby wakes up in the morning, check if they have watery, goopy-looking eyes, or a crust on their eyelids and lashes. Your baby shouldn’t feel any pain. What is the best solution?

  • Gently wipe your little one’s lids with a warm, damp towel or tissue. 
  • Also, talk to your pediatrician if it doesn’t resolve itself within a few days. 
  • They might prescribe you an ointment and instruct you to massage the tear duct in the inner corner of the eye. 
  • You don’t need to stress over it because for some babies it lasts just for a while, but most blocked ducts will resolve by themselves by the baby’s first birthday or earlier.

Tests and Vaccinations:

In the 9th week of your child’s age, there are no specific vaccines to be administered as long as you’ve got all the previous vaccines fully completed.

Postpartum baby tips: Week 9 after birth

Understanding your baby’s behavior

  • When your little one is a little too excited, their cooing and grunting could resemble gargle-like laughter. 
  • At times, your baby will be more responsive and give you some adorable little smiles. 
  • By this age, with supervised tummy time, they’ll be able to lift their head properly and look straight ahead. 
  • Although not for long, your little one can use their arms to support themselves. 
  • Your baby will repeatedly keep falling over and still try to keep doing it. Make sure they don’t hurt themselves on a hard surface.

Understanding your baby’s developing senses

  • This is the best time to develop your baby’s auditory senses. 
  • Collect various items from your home that will make all sorts of sounds, it can be some squeaky toys, bubble wrap, crumply bags, steel items, etc (avoid any electronic sounds). 
  • While looking at your baby, start making some sounds but don’t show them the object right away. 
  • Show the object as your baby starts understanding the sound and make the sound in front of them. 
  • You should let your baby try to make the sound by themselves too. 
  • Moreover, there could be an increase in drool, chances are that at this point their salivary glands are kicking into overdrive.
  • After a smile, now your baby can recognize you and other caregivers. 
  • During tummy time, you might see super baby strength as their head and shoulders lift off the play mat. 
  • They also start reaching towards toys that will straighten their legs

Understanding your baby’s health risks


  • Sometimes the blocked tear duct can turn to be conjunctivitis, most commonly known as pinkeye. It might affect one or (sometimes) both eyes and it’s caused by a bacterial or viral infection. 
  • Pinkeye is notoriously common among babies so don’t worry! 
  • Some of its yucky symptoms include redness in and around the eye and green or yellow mucus that will practically seal the eyelids shut. 
  • Consult your pediatrician and they will most likely prescribe you some eye drops that will make it go away in a few days.  
  • However, it’s super contagious. So, to keep the infection from returning, keep all clothing items hygienic and your hands well. 

Diaper Rash: 

As babies have extra sensitive skin, sometimes they might get a diaper rash. So, treat it using breast milk or diaper rash cream. Moreover, if it gets severe over time, get it examined by the doctor as it could be a skin-related condition.

The mother's body after childbirth: What is happening in your body in the ninth week after giving birth?

Your breastfeeding time

  • By now the tendency to feed your little one on both breasts will be even stronger than ever. Although it isn’t true, most mothers might feel as their baby is around 2 months old, they might need more food. 
  • There’s no need for additional food items or formula milk if your baby is happily breastfeeding, gaining weight, and sleeping. 
  • They might have started teething too so they might end up suckling at your breast a little harder than usual.

Your postnatal depression

  • You can experience postnatal depression at any time during the first year of your baby’s life. 
  • You might feel overwhelming guilt or feelings of failure, or you feel like everything is going wrong and it’s all your fault. 
  • Almost one in ten women suffer from postnatal depression. 
  • Remember that you’re not alone. 
  • If you experience any signs, seek help as soon as you can. Never hesitate to ask for help too!

You have to return to work

  • The end of your maternity leave might be approaching. 
  • This brings in lots of emotions as some moms are looking forward to returning because they love their jobs and are thrilled about talking to other adults. 
  • Meanwhile, other moms are torn up about leaving their children with their nannies or daycare providers. 
  • Every other working mom has to deal with some guilt. 
  • It’s a big transition so we would recommend you to take it slowly and accept yourself and all the emotions. 
  • Try to slowly make yourself adjust to the daily grind again. It’ll also make you feel like you’re in-the-loop on your first day back. 
  • On your first day back to work, your baby might be teary but we promise you it’ll get easier. 

Your first-time having sex post-baby

  • Depending on how your labor went and your recovery process, sexual intercourse post-baby can be a bit scary. Let’s not forget you’re exhausted too. 
  • Usually, at your six-week postpartum appointment, your doctor gives you the all-clear for intercourse. 
  • But it doesn’t necessarily mean that you’re physically or emotionally ready. If you have any concerns, talk it out with your partner. 
  • Remember you don’t have to have sex to be intimate with your partner. Learn some new ways to get it on!

Final Thoughts

Your nine-week-year-old baby has grown up to learn a lot. They recognize lots of things too. Everyone at home must be ecstatic about your baby rollicking in laughter and fun. Also, they discovered their hands and most likely tried to do all sorts of things with them. Parenting is tiring, stressful, overwhelming, and fulfilling. It’s everything at the same time. There are days when everything will be too much but remember you’re just a human! So give yourself some credit! You’re doing a great job!

FAQs-our 9-Week-Old Baby: Development, Growth, Health, Postpartum, New Baby Tips & Recommended Products

1. What can my 9-week old baby see?

Their 3D vision has developed by now so they can see faces. You’ll often see them staring intently at everyone around them. Moreover, if an object or sound is eight inches in front of them, it will catch their attention and will look around for the sound.

2. How do I stimulate my 9-week old baby?

  • Cooing & Gurgling: Try to talk to your baby often.
  • Switch Swat: Simply dangle objects (such as rattle) so that your baby can swipe at them.
  • Toy Gaze: When your baby is lying on their tummy and you want them to look up, simply play with their favorite toy in front of them.
  • 3. How often should a 9-week old baby be nine-week?

    Infants usually eat after every 2 to 3 hours, or at least 8 to 12 times throughout the day. Babies usually drink around 1 to 2 ounces during each feeding.

    Reviewed By-

    Nimrat, Pediatrics

    Nimrat, Pediatrics

    Dr. Nimrat S Sidhu is a practicing pediatrician for about 5 years now and holds an MD pediatrics degree. She was the topper of her batch, has always had a keen interest in her core medical field, and is specially trained for neonatal resuscitation.

    On behalf of the editorial team at Parenthoodbliss, we follow strict reporting guidelines and only use credible sources, along with peer-reviewed studies, academic research institutions, and highly respected health organizations. To learn about how we maintain content accurate and up-to-date by reading our medical review and editorial policy.

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