The 4th trimester is over, now what? Baby's sleep at 3-6 months

A guide for getting onto a sleep schedule for mama and baby

By Dr. Kelsey Alford, CPNP-PC, DNP

Congrats mamas and dads, you made it through the fourth trimester! Those first few months are such an important time for bonding and learning how your baby is communicating with you. There is a lot of figuring out from which cry is for hunger and which is due to tiredness. I'm sure you've mastered hush little baby and which rocking motion can get your sweet cherub off to sleep.

As your baby enters the 4th month you’ll soon see that there are more periods of wake and more defined periods of sleep, but there likely isn’t much of a schedule at this point right?! So where do you start after the fourth trimester is over? You want to develop good sleep foundations, but don’t know where to begin.

Newborn sleep vs sleep for your 3 to 6 month old

First, let’s talk a little bit about newborn sleep versus the sleep your little baby now has. In the newborn phase (about the first two months) your baby went right into what is called “REM” or dreaming sleep and spent 50% of their time during sleep here. REM is most important for growth and development formation and boy were they doing A LOT of growing. Now about 4 months babies go into “Non-REM” sleep first, which they will continue to do for the rest of their life (Tham, et al. 2017). Remember they aren’t “regressing”, but progressing in their sleep development.

Now that they are in their new sleep cycle arena you can start to teach them a little more about how to sleep. This is truly one of the first of many teacher moments you will have as a parent so try to enjoy it! 

Baby Sleep Schedule 4-7 months

Steps to lay a strong sleep foundation:

1. Start to notice a nap pattern.

Typically babies at about 4-6 months start to have 3 naps per day. The easiest nap to start with working on independent sleep and schedule is the morning nap. This is because their drive to sleep is often the highest at this time. When you start to notice tired signs (ie; rubbing eyes, zoning out or not paying attention to the activity, pulling at ears, more clingy to the caregiver) and their wake window is almost complete (see below), place the baby in their safe sleep space, swaddle (if using), use pacifier (if using), then make sure baby is a little drowsy, but still awake. (See on sample baby sleep schedules here)

2. Get out of that swaddle!

American Academy of Pediatrics (AAP) safe sleep guidelines recommend getting out of the swaddle once your baby has started to roll and if they haven’t started to roll yet, they will soon! And when making the transition don’t use any transition swaddles such as weighted swaddles. Weighted swaddles or weighted blankets, which can place too much pressure on a baby's chest and lungs. More on transitioning out of the swaddle here

3. Move from the bassinet to the crib.

With rolling and independent sleep comes baby needing more space. Whether your baby was in a standard bassinet or the SNOO it’s time to let them spread their wings. Remember nothing else in the crib except baby and an arms free sleep sack. The crib can be in the parents bedroom until you feel ready to transition to their own room (AAP recommends ideally for at least the first 6 mo. in parents room). More on making this transition on my blog here.

Perfecting the wake window

As a new parent, I thought following a by-the-clock nap schedule was absolutely a thing from early on! Well, now that I've been in the sleep business for years I know that wake windows are magic. There is an art and science to perfecting the wake window for your baby. It helps with independent sleep for baby, longer naps for baby, and more warm coffee for parents!


# of Naps

Wake Window

3 months


90-100 minutes

4 months


2 hours

5 months


2.25 hours

6 months


2.5 hours

*This is a general guide based on average for age wake and sleep times

Sleep Training

“Is sleep training something that every baby needs?”. Nope! Sleep training or sleep education is needed when a child is over 4-6 months and experiencing any of the following:

1. Having a hard time falling asleep independently

2. Is waking more than once a night (in an 8-12 hour period)

3. Having short naps despite following age appropriate wake windows.

Of course here or there it can be a twice-wakeup, but if they are waking 3-4 times a night then that, my friend, is not good for parents or the baby’s physical and mental health long-term.

Now I know that sleep training can be controversial and we won’t get into too much of that here because ultimately the beauty of parenthood is that YOU GET TO DECIDE WHAT WORKS FOR YOUR FAMILY! I never, ever, tell a family that they need to sleep train, but it absolutely is available to help children learn to fall asleep and stay asleep on their own without any harm to the attachment between parents and child long term (Gradisar et al., 2016).

Sleep training can sometimes be overwhelming! Even if this is not your first child there can be a number of reasons why support may be helpful. I love that I get to support families through a challenging time because I truly believe we should not parent alone.

I started Nested Sleep because I want to give parents a village that can often be hard to find these days. If you want to chat or need 1:1 support through your sleep journey book a free call with me here.

If you feel lost, give yourself some grace! This is all so new for both you and baby. Try to step back and remember the keys to success are consistency, patience, and time. If you need more guidance check out my newborn sleep guide here with more sample schedules, sleep environment tips, and 1:1 support when needed!



Gradisar M, Jackson K, Spurrier NJ, Gibson J, Whitham J, Williams AS, Dolby R, Kennaway DJ. Behavioral Interventions for Infant Sleep Problems: A Randomized Controlled Trial. Pediatrics. 2016 Jun;137(6):e20151486. doi: 10.1542/peds.2015-1486. PMID: 27221288.

Rachel Y. Moon, Rebecca F. Carlin, Ivan Hand, THE TASK FORCE ON SUDDEN INFANT DEATH SYNDROME AND THE COMMITTEE ON FETUS AND NEWBORN; Sleep-Related Infant Deaths: Updated 2022 Recommendations for Reducing Infant Deaths in the Sleep Environment. Pediatrics July 2022; 150 (1): e2022057990. 10.1542/peds.2022-057990

Tham, E., Schneider, N., & Broekman, B. (2017). Infant sleep and its relation with cognition and growth: a narrative review. Nature and Science of Sleep, Volume 9, 135–149.

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