The Conundrum of Prematurity: “But They’re Getting So Big!”

There is nothing more joyous or more adorable than a doughy, pudgy little chunkster of a baby, right? You know, the one with the cute Budda belly, thigh rolls for days and cheeks so pinch-and-kissable…ah, the life. And then with twins there are two of them – #omg #cutenessoverload #pudgefordays. After all a baby that is fat, smiling and happy must be healthy, right?

This concept of “baby weight” and “fat babies = healthy babies” dawned on me back in the early days of the NICU when family would ask, “How much do they need to weigh before coming home?” It literally was a question that was asked more than two dozen times by family, friends and those around us that were not medical personnel. Why was everyone so damn concerned about how much the kids weighed and not with whether or not they could exist without breathing support? Or feed via a bottle? Or coordinate their breathing while taking a bottle and not going into bradycardia (brady, for short)?

As we traversed the NICU we learned that there were many signs of health and many things to monitor when learning to manage prematurely born infants. There is also the topic of “corrected age,” which looks at developmental milestones as a function of chronological age vs. gestational age (more on that later). In fact, weight was rarely discussed except to ensure that any body weight lost post-birth was promptly regained; weight was not even a criterion for hospital release! What was? A NICU nurse referred to the short list as “START.”

1) Self-regulating body temperature and heart rhythms

2) Taking all milk by mouth

3) Ability to breathe without any support (although some babes are released on oxygen)

4) Regular excretion (pooping/peeing)

5) The car seat test

While this list is by no means exhaustive it is a good list of basic tasks that all newborns must accomplished prior to being released.

Thankfully our babies were released at one month of age (chronological age) and we were cleared to go home. Having been born at 33 weeks (gestational age) they were doing pretty good. But before this happened our occupational therapist (OT) had a long sit-down with us. It was likely the most life-changing conversation. Simply stated she said, “You don’t have normal babies. You have babies that were born 2 months early and their chronological age must be “corrected” with respect to their gestational age.” What does this mean? Since usual or normal full term is 40 weeks here is how 33 weekers is “corrected.”

Comparison of Gestational, Chronological and Corrected Ages for Children Born 7 Weeks Premature

Gestational Age Chronological Age Corrected Age
33 weeks 0 weeks -7 weeks
34 weeks 1 week -6 weeks
35 weeks 2 weeks -5 weeks
36 weeks 3 weeks -4 weeks
37 weeks 4 weeks -3 weeks
38 weeks 5 weeks -2 weeks
39 weeks 6 weeks -1 weeks
40 weeks 7 weeks 0 weeks
—– 8 weeks 1 week
—– 9 weeks 2 weeks
—– 10 weeks 3 weeks
—– 11 weeks 4 weeks
—– 12 weeks 5 weeks

So what does this mean? Why do we correct age? Why is this important? How long do we need to correct age for? What impact will this have on the kids? The answer? Every child is different. Let’s break this down in a simple, concise way.

What does ‘corrected’ age mean and why do we correct for age?

The term “corrected age” is nothing more than a way to observe a baby based on their “age” had they been born full term. The American Academy of Pediatrics (AAP) has developed a guide (available by clicking here) that shows the average age most kids develop certain skills. Things like the ability to self-soothe, make direct eye contact, sit up, babble and a host of other social, cognitive and motor skills. But when a baby is born prematurely it has an effect on this timeline. In other words: some milestones may be delayed and may show up on or around their “corrected” age. For example at 4 – 8 weeks old most babies born full term start to smile and engage with those adults around them. Our babies didn’t start to actively smile until they were around 4 months. When we correct for their “prematurity” we can clearly see that they would be “2 months corrected.” And when we look at the AAP guidelines we see that this would then fit into the “normal” curve.  Basically, for developmental milestones (Social, Cognitive and Motor) it’s important that parents of babies prematurely born correct to their gestational age – this also means that doctors need to correct as well and allow the extra time needed should babies require.

How long do we correct for age?

Most developmental milestones should correct themselves around 24 months, or 2 years of age. This seems to be what the peer-reviewed literature states as well as the AAP. Of course if we’re concerned with a particular milestone then we should always go back to our pediatrician and openly discuss.

So what does all of this mean? Is weight important? Yes. Of course it is. It’s an indicator of nutrition and how well our kids are thriving from a purely growth-perspective. But there is so much more as parents of premature babies to think about. It means that while our preemies may not “look like preemies due to their size” despite them being 10 month old may still act and behave like an 8 month old. It means that your child at 14 months who is speed walking may leave my crawlers in the dust, and this is ok. We’ve accepted this fact. It’s all a part of parenting. But above all what this should tell us and any parents is as follows:

  • All children develop differently
  • Children born premature go by “corrected age”
  • If you are concerned about a particular milestone simply speak to your pediatrician

But please: stop telling us parents of preemies that our “big babies who were once so little and tiny” are no longer premature. They are and will be until they grow out of it, and even still sometimes the scars of being born early are with them forever.