When a baby is born prematurely, its development generally occurs at a different rate than a full-term baby. That is why growth milestones should not be evaluated taking into account their chronological age but rather their corrected age , even up to two years due to the process that takes place during that period of time.
What is corrected age?
To explain the meaning of the corrected age, we must be clear about two concepts:
- Gestational age : it is the time that the pregnancy has lasted and is counted in weeks, from the first day of the last menstrual period until the day of delivery.
- Chronological age : is the time elapsed after birth. It is generally counted in days, weeks, months and years.
The corrected age , meanwhile, is the age the baby would have if it had been born at 40 weeks. In other words, the number of weeks in advance must be subtracted from their chronological age. Through this calculation, the maturity of the baby is “corrected” or “adjusted” according to the intensity of its prematurity.
If a baby was born at week 34 (that is, 6 weeks earlier), and his chronological age is 3 months, his corrected age would be one and a half months:
12 weeks (or 3 months) – 6 weeks = 6 weeks (or a month and a half).
What is corrected age used for?
The corrected age is the one that must be taken into account to evaluate the physical and neurological development of the baby , both in weight and height and head circumference. To weigh and measure like a baby born at 40 weeks, the premature will have required a time that will depend on its gestational age.
This calculation should also be taken into account to start complementary feeding, so they should start eating at six months of corrected age. For preterm infants who breastfeed, this “extra” time of exclusive breastfeeding is very beneficial.
There is a single exception in the case of vaccines , since these must be administered taking into account their chronological age, so they must receive the vaccines at the same age as full-term babies.
Why should the corrected age up to two years be taken into account?
The corrected age must be taken into account at least up to 2 years, because the maturation rate of a premature baby is slower and it is calculated that it is precisely in that period of time in which it can be equated to the growth of a baby born to finished.
I personally have the experience of being the mother of a late preterm baby (born at week 34), who initially did not need special neonatal care despite weighing less than 2 kg. His lungs were working perfectly and he quickly latched onto his chest, thereby quickly gaining weight. That is to say, in principle we hardly notice the prematurity of our daughter.
However, as he grew older, a sequel did manifest for not having reached 40 weeks of gestation : having little strength in his neck and not turning over when in theory he should – generally between 5 and 6 months -. Her psychomotor development corresponded to a baby about 8 weeks younger, so we had to attend a couple of therapies to learn to do exercises that would strengthen her muscles and thus stimulate her interest in rolling over. At that time we verify that the corrected age is very important to assess in a more accurate way if the baby is evolving at a correct rate, or if, on the contrary, it needs some type of early stimulation or special therapy.
In Babies and More | Parents of premature children claim to be able to school their children according to their corrected age, and not chronological
