Four Month Baby Development Milestones

From the moment you bring your little one into this world, they’re growing physically, emotionally, socially and more. As they reach their four month mark, they’ll have already hit many exciting milestones, including improved mobility, a more regular sleep schedule, interest in more diverse foods, more curiosity, more language & other communication efforts, and so much more! Let’s go over what to watch for, and how these are indications of their development as a whole.

In terms of their social and emotional developments, it’s right around this time they’ll start to turn into what we like to call “social butterflies.” They’ll begin to smile on their own to get your attention or in response to a happy feeling, in addition to trying to laugh (they might not be quite there yet, but you’ll be able to hear their first attempts!). You may also begin to notice that their language and communication efforts are maturing during this time– not only will they start making “oooohhh” and “ahhhhh” sounds, they’ll also start to turn their head at the sound of your voice and look at you when you talk.

Even more exciting– your baby will begin to recognize familiar faces now! They will likely start to give you and other family members/friends they’re around a lot a big smile when you/they walk into the room. They can also mimic certain facial expressions or sounds and respond to affection. Because they’re really starting to come into their own right around the four month mark, you may also begin to notice a difference in how they’re expressing their needs– for example, they may have a different cry for hunger vs. tired vs. irritation vs. pain.

In terms of their physical developments, at four months, your little one will likely have doubled their birth weight. At this age, babies typically gain about 1 to 1 ¼ pound and grow about 0.5 inches per month. With this new weight and height, comes new muscle! They’ll now be able to hold their head steady without support from you holding them, hold onto a toy when you place it in their hand (often even swinging at the toy if they’re really excited!), and pushing up onto their elbows when onto their tummies. They may even start rolling from belly to back and should be able to push down with their legs as you help them stand up on a flat surface. (This is a great way to build leg strength!).

While breastmilk or formula is all your baby needs at this age, your little one could be beginning to show signs of interest in solid food. While you should always check with your pediatrician before introducing it into their diet, they may be beginning to show they’re ready if they’re holding their heads up, opening their mouth near your food or reaching for it, or other things of that nature.

Finally, let’s talk about their sleeping habits– in general, your 4-month-old needs 12 to 16 hours of sleep per day. During the day, they will be taking four naps totaling an average of three to four hours of daytime sleep. While they may be getting over, the same habits should apply– they should still be sleeping in their own cribs, with no loose objects around, until around the 6 month mark. While they will have more regularity in their sleeping schedule at this time, you may be faced with the dreaded sleep regression (these are often a result of all the growth your little one’s body is undergoing). Although not permanent, ways to combat this can include laying your baby down awake but sleepy, using their pacifier, relying on their established routine, and more.