The Molecular Apgar Score: A Key to Unlocking Evolutionary Principles

Abstract

One of the first “tools” used for systematically evaluating successful newborn transitional physiology at birth was the Apgar Score, devised by Virginia Apgar in 1953. This objective assessment tool allowed clinicians to immediately gauge the relative success of a newborn infant making the transition from the in utero liquid immersive environment to the ex utero gas environment in the delivery room during the first minutes after birth. The scoring system, although eponymous, is generally summarized as an acronym based on Appearance, Pulse, Grimace, Activity, and Respiration, criteria evaluated and scored at 1 and 5 min after birth. This common clinical appraisal is a guide for determining the elements of integrated physiology involved as the infant makes the transition from a “sea water” environment of 3% oxygen to a “land” environment in 21% oxygen. Appearance determines the perfusion of the skin with oxygenated blood—turning it pink; Pulse is the rate of heart beat, reflecting successful oxygen delivery to organs; Grimace, or irritability, is a functional marker for nervous system integration; Activity represents locomotor capacity; and, of course, Respiration represents pulmonary function as well as the successful neuro-feedback-mediated drive to breathe, supplying oxygen by inspiring atmospheric gas. Respiration, locomotion, and metabolism are fundamental processes adapted for vertebrate evolution from a water-based to an atmosphere-based life and are reflected by the Apgar Score. These physiologic processes last underwent major phylogenetic changes during the water–land transition some 300–400 million years ago, during which specific gene duplications occurred that facilitated terrestrial adaptation, in particular the parathyroid hormone-related protein receptor, the β-adrenergic receptor, and the glucocorticoid receptor. All these genetic traits and the gene regulatory networks they comprise represent the foundational substructure of the Apgar Score. As such, these molecular elements can be examined using a Molecular Apgar evaluation of keystone evolutionary events that predict successful evolutionary adaptation of physiologic functions necessary for neonatal transition and survival.

Factors Associated with Apgar Score among Newborns Delivered by Cesarean Sections at Gandhi Memorial Hospital, Addis Ababa

“…Scores obtainable are between 0 and 10, with 10 is the highest possible score. A total score of 7-10 is considered "normal," and a lower Apgar score indicates depressed vitality [5]. However, several possible causes of low Apgar scores exist, such as perinatal asphyxia and congenital infections [6][7][8][9].…”

Prognostic Value of Serum Magnesium Level as a Marker of Endothelial Dysfunction in Premature Birth Neonates

“…Тому що було показано, що оптимізоване раціональне застосування магнію при наданні медичної допомоги обумовлює кращий стан дитини після народження [11]. Перераховане стосується і післяпологової адаптації завдяки з'ясованій нами позитивній кореляції між рівнем дихальної недостатності і рівнем оксиду азоту -відомим еволюційним пристосувальним компонентом [12] альтернативного, на відміну від кисню, енергопостачання.…”

Associations between Apgar scores and children’s educational outcomes at eight years of age

“…Apgar scores can also be used as a physiological indicator of how well a newborn is making the transition from in utero to the ex utero environment 4 . For example, the skin colour is evaluated to determine the perfusion of the skin with oxygenated blood; heart rate reflects the success in the delivery of oxygen to organs; reflex irritability can be used as a marker for nervous system integration; muscle tone represents the locomotor capacity of the newborn; and respiratory rate represents pulmonary function, which facilitates the neuro‐feedback‐mediated effort to breathe 4 …”

“…For example, factors such as maternal sedation or anaesthesia, congenital malformations, trauma, gestational age, infections and low birth weight often affect Apgar scores 2,5 . The health status of newborns may be misclassified because some components of the Apgar score such as skin colour, muscle tone and reflex irritability are partially subjective by nature—that is, the scores are affected by newborn assessment skill (inter‐observer variability) and the context of the delivery 2,4 …”

“…For instance, according to the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists, ‘Apgar score alone cannot be considered to be evidence of or a consequence of asphyxia’ 2 . As neonatal resuscitation should be initiated before one minute of birth, the Apgar score is no longer used as a valuable determinant to initiate resuscitation in contemporary clinical practice, but it can be used to evaluate the effectiveness of resuscitation 2,4 . These limitations may make the interpretation of ‘what the Apgar score is measuring’ or even ‘what low Apgar score is a risk for’ unclear 5 .…”