Remembering the classics: How Old is This Baby?
Alan Jay Schwartz, MD, MSEd and Lynne G Maxwell, MD
Original Article
Engle WA; American Academy of Pediatrics Committee on Fetus and Newborn. Age terminology during the perinatal period. Pediatrics. 2004 Nov;114(5):1362-4. doi: 10.1542/peds.2004-1915. PMID: 15520122.
A PAAD reader recently suggested PAAD consider “best” definitions of age of newborns, especially neonates. Clinical anesthesiologists need to know an infant’s age when providing anesthetics because physiologic maturation and potential instability with attendant morbidity is age related.1
In 2004 the American Academy of Pediatrics (AAP) published a Policy Statement, “Age Terminology During the Perinatal Period”2 that has been reaffirmed by the AAP in 2008 and 2021. The AAP Policy Statement indicates:
“Consistent definitions to describe the length of gestation and age in neonates are needed to compare neurodevelopmental, medical, and growth outcomes. The terms "gestational age," "postmenstrual age," "corrected age," and "postconceptional age" have frequently been defined unconventionally…misapplied…or left undefined…Inconsistent use of terminology limits the accurate interpretation of data on health outcomes for newborn infants, especially for those born preterm or conceived using assisted reproductive technology. The purposes of this statement are to review conventional definitions of age during the perinatal period and to recommend standard terminology.”2
The AAP Policy Statement recommends:
1. Standardized terminology should be used when defining ages and comparing outcomes of fetuses and newborns. The recommended terms…are:
* Gestational age (completed weeks): time elapsed between the first day of the last menstrual period and the day of delivery. If pregnancy was achieved using assisted reproductive technology, gestational age is calculated by adding 2 weeks to the conceptional age.
* Chronological age (days, weeks, months, or years): time elapsed from birth.
* Postmenstrual age (weeks): gestational age plus chronological age.
* Corrected age (weeks or months): chronological age reduced by the number of weeks born before 40 weeks of gestation; the term should be used only for children up to 3 years of age who were born preterm.
2. During the perinatal period neonatal hospital stay, "postmenstrual age" is preferred to describe the age of preterm infants. After the perinatal period, "corrected age" is the preferred term.
3. "Conceptional age," "postconceptional age," "conceptual age," and "postconceptual age" should not be used in clinical pediatrics.
4. Publications reporting fetal and neonatal outcomes should clearly describe methods used to determine gestational age.
Thus, we would urge all of you to stop using the commonly used “post-conceptual age” when discussing or writing about newborns! Send your thoughts and comments to Myron who will post in a Friday reader response.
References
1. Disma N, Veyckemans F, Virag K, et al. Morbidity and mortality after anaesthesia in early life: results of the European prospective multicentre observational study, neonate and children audit of anaesthesia practice in Europe (NECTARINE). British journal of anaesthesia 2021;126(6):1157-1172. (In eng). DOI: 10.1016/j.bja.2021.02.016.
2. Engle WA. Age terminology during the perinatal period. Pediatrics 2004;114(5):1362-4. (In eng). DOI: 10.1542/peds.2004-1915.