Premature baby sleep is not like full-term baby sleep. There are some important differences, and some slightly different priorities. These different priorities will help shape your preemie’s sleeping pattern. Before I launch into the particulars of premature baby sleep, let’s define some terms and describe some important features of preemies.
What is a Premature Baby?
By definition, a “full-term” baby is born between 38 and 42 weeks gestation. And now of course I need to define “gestation”: For purely conventional reasons, as you will see, gestation is calculated from the date the the mother’s last menstrual period started. Now, if you were paying attention in Biology class, or at least in Health class, you know that there is no possible way that you can get pregnant on the first day of your menstrual period! Why pick a non-sensical date as the beginning of gestation of a baby that hasn’t been conceived?
The answer is simply that the first day of a menstrual period is a date that most mothers can fix with a fair amount of accuracy. Conversely, the date of the sexual encounter that actually resulted in conception is difficult or impossible to pin down. That is why I say the date is “purely conventional”. It’s an easy date to fix. That’s all.
Why do we define “full term” as 38-42 weeks? Any pregnancy longer than 42 weeks is considered “post-dates”. Overdue pregnancies have issues of their own. Happily, sleep tends not to be among them. But for babies born early, sleep can be an issue.
The Fourth Trimester
In a funny way, even full-term babies are “born early”. We humans have large brains. It’s a good thing, too, because we need those big brains to survive in this big, cruel world. We certainly couldn’t do it with these ridiculously inadequate bodies we’ve evolved!
Big brain means big head. And big heads are difficult to pass through the “birth canal” (my all-time favorite euphemism!) So babies are born just about at the time when, if they were to stay inside any longer, they’d get stuck and never come out. And we’d have no more humans. Babies are born, therefore, prior to the time when the rest of the body is “ready” to be born. The baby has more growing and developing to do, but she must do it out here in the world, all because of that big brain.
Pediatrician Harvey Karp, in his wonderful book “Happiest Baby on the Block“, describes what he calls the “fourth trimester”. That is the period of time the baby is still developing, though she’s already been born. According to Karp, what hasn’t fully developed yet, among other things, is the baby’s ability to self-soothe. Karp argues that if the baby could stay inside for 3 more months (gasp!) she’d be born fully able to put herself down to sleep, as most 4 month old babies can.
The 3 Things Preemies Need to Do
What is true of full-term babies is even more true for premature baby sleep. These babies are even further away from the end of Dr. Karp’s fourth trimester. So there are many more developmental phases that preemies must accomplish before we can even worry about self-soothing.
If your baby is born prematurely, she will very likely have to stay in the hospital until she can do three things on her own: Remember to breathe; Remember to eat; and keep a normal body temperature. Once she can do all three, there is nothing more the hospital can do for her, and you can take her home!
Fetuses obviously do not breathe air, so they do not develop the ability to breathe air until fairly late in gestation, generally around 32 weeks. The problem, especially with male infants for some reason, is that they “forget” to breathe. So sometimes they stop breathing “by accident”. This is why in the neonatal intensive care unit (NICU), the baby is hooked up to monitors. If she should stop breathing, the nurse will be alerted. She’ll give the baby a little jostle and remind the baby to breathe again!
Need a SLEEP COACH?
Fetuses swim around in lovely amniotic fluid at a toasty 98.6 degrees Fahrenheit, so they don’t need to regulate their own temperature. Born early, some babies need to be heated up or their body temperatures would drop to room temperature, like a reptile’s would. This is the reason for the isolette, what we commonly call an “incubator”.
Finally, fetuses are fed through that big juicy umbilical cord! They don’t need to remember to eat. But if they are born early, they must. So the hospital will keep a premature baby until she can eat and gain weight as much as she would if she were still “inside”.
The doctors and nurses at the NICU may tell you that you can expect the baby to go home with you at around her due date. But in practice, she might be able to do these three things before her due date.
What About Sleep?
When the preemie is not eating, she is sleeping. Premature babies spend at least 20 hours sleeping. Eating is essential for the premature baby to grow, but so is sleep! So NICUs tend to be quiet places without a lot of sound and commotion.
When your premature baby comes home, she’ll need to do a lot of both sleeping and eating. There are some important things to know about preemie sleeping and eating, and we’ll deal with them in future posts.