Baby Care: 12 Week Old Baby

Feb 15, 2022

Your baby is now 3 months old. You have met a new milestone!

The first 12 weeks of life can be challenging for new parents and their babies. Getting to know your baby and becoming familiar with what works can take a few months of trial and error. If your baby has been fussy and prone to lots of crying, feel reassured that there are probably easier days ahead. There is generally a steady improvement in fussiness from now on, and babies tend to be a little easier to handle. It’s unlikely, though, you’ll wake up one morning this week and find they are suddenly less demanding. Change can take time.

You will have found what works to soothe and calm your baby, how they like to be held, how often they like to feed and what you can do to entertain them. Although each day will be a little different, there will be more of a pattern or routine to your days, and you may even find yourself with moments of time to yourself.

If you feel up to it, perhaps arrange for someone to watch the baby while you and your partner go out for a date: see a movie, go out for a meal, or go for a long walk and talk. Make an agreement not to talk solely about the baby, though. Willing grandparents would probably love the opportunity to watch their grandbaby.

Do what feels right for both you and your partner. Make time for your partner. Even if you don’t make it out of the house together, having some couple time is valuable. Healthy, strong couples see parenting as a shared process and their children can only benefit from this approach.


Many babies go through a growth spurt at this age and want to feed more often for a few days. You could feel as if you are chained to your recliner due to all the feeding. Growth is directly related to caloric intake and babies don’t always grow at a steady pace—they can literally grow overnight. Research shows that children generally grow faster during spring and summer as well.

Your baby still doesn’t need any other food besides your breastmilk or formula. Know that what they are getting is all they need at this stage.

The recommended formula amount from 5 days to 3 months is 2.5 ounces per pound of body weight, per day. From 3 to 6 months, this amount may decrease slightly. Remember to never try to force your baby to finish a bottle. Watch for cues that he or she is full and throw away whatever formula remains if you are formula feeding.


Keep placing your baby on their back to sleep. Very soon your baby will start rolling. This is generally from a back to front direction first. Then, after a short time they learn to roll back the other way.

Supervised tummy time every day is important and will help them to practice and perfect their rolling skills. If your baby is starting to show signs of wanting to roll over, it is time to stop swaddling. Rolling over while in a swaddle, especially with their arms restrained, is dangerous. Continue to keep loose blankets out of the crib and use blanket sleepers or footed pajamas for sleep. Safe sleep recommendations are for the first year of your baby’s life.

If you have been feeding or rocking your baby until they go to sleep, you might find this becomes an issue around 3 months of age. Babies need to learn to go to sleep on their own by self-soothing themselves to sleep. Try laying them in their crib when they are drowsy but not quite asleep. During the night, babies often only slightly wake up and will go back to sleep relatively easily after being fed.

If you are breastfeeding at night, you may find that sitting up in your bed and feeding is the most comfortable option. Just remember to not sleep with the baby in your bed. Positioning their crib or bassinet next to yours will be the safest option for your little one.

If you are bottle feeding, having the baby sleep next to you also makes it easier for feedings to be shared between you and your partner. Try having formula pre-made and ready to go in the refrigerator, as it will also help make those overnight feedings easier.

Behavior and development

Watch your baby hold a rattle in their hand and wave it around. Their grip can be surprisingly strong, and they will learn to reach and grab objects which interest them at this age. Your baby will be able to kick and extend their legs, and may even be trying to put their little feet towards their mouth.

Some babies might still be spitting up milk at 12 weeks due to reflux. The sphincter, a circular muscle at the top of a baby’s stomach, can be relaxed which allows the contents of their stomach to easily flow up their esophagus food pipe and into their mouth. Unless your baby is failing to gain weight or there are other feeding problems, there is no reason to be concerned. For most babies, reflux improves with time and stomach maturity.


Your baby will be more predictable with their crying now and you are probably more successful at figuring out what is wrong.

Sometimes, however, it can be very hard to tolerate a baby’s crying, especially when it has gone on a long time and nothing seems to help. Be prepared to have some days which are more challenging than others and ask for help. Let your partner know that you are struggling, especially if you find yourself getting frustrated, overwhelmed, or angry.

Remember never to shake your baby to make him stop crying. Place your baby in their crib and close the bedroom door until you calm down. It is okay to let your baby cry. Do not go back in until you are feeling better.


Your days will still be fairly controlled by your baby’s needs at 12 weeks. Perhaps your little one is sleeping for a longer period overnight and is more wakeful through the day. Avoid the temptation to try to keep them up during the day without a nap. An overtired baby can have more trouble going to sleep at night. Try to develop and be consistent with a bedtime routine that is enjoyable for both you and your baby. A bedtime routine will help your baby settle and cue them that bedtime is coming.

Other things to expect

If you are breastfeeding, you may have found your baby isn’t having as many dirty diapers. It is common in the first couple of months for babies to poop every time they feed, but this tends to slow down around this age. Breastfed babies rarely become constipated.

It’s normal for your baby’s stools to have a pasty consistency if you are formula feeding. It's also normal for it to be a greenish color due to iron contained within the formula.

Your baby can focus more clearly with their eyes now and can track objects when they move. In the next month or so, their color vision will mature. This is a stage of rapid changes in your baby’s eyes which need to be protected from bright light. Avoid going out in harsh, direct sunlight if possible. If you are breastfeeding, ensure your diet is high in green leafy vegetables, yellow vegetables, and a wide range of fruits. These all contain antioxidants and specific nutrients which will help protect your baby’s retina against light damage.

The information of this article has been reviewed by nursing experts of the Association of Women’s Health, Obstetric, & Neonatal Nurses (AWHONN). The content should not substitute medical advice from your personal healthcare provider. Please consult your healthcare provider for recommendations/diagnosis or treatment. For more advice from AWHONN nurses, visit Healthy Mom&Baby at