The goal of this study was to examine the degree to which children born within the “normal term” range of 37 to 41 weeks’ gestation vary in terms of school achievement.
This study analyzed data from 128 050 singleton births born between 37 and 41 weeks’ gestation in a large US city. Data were extracted from city birth records to assess a number of obstetric, social, and economic variables, at both the individual and community levels. Birth data were then matched with public school records of standardized city-wide third-grade reading and math tests. Specifically, we assessed (1) whether children born within the normal term range of 37 to 41 weeks’ gestation show differences in reading and/or math ability 8 years later as a function of gestational age, and (2) the degree to which a wide range of individual- and community-level social and biological factors mediate this effect.
Analyses revealed that gestational age within the normal term range was significantly and positively related to reading and math scores in third grade, with achievement scores for children born at 37 and 38 weeks significantly lower than those for children born at 39, 40, or 41 weeks. This effect was independent of birth weight, as well as a number of other obstetric, social, and economic factors.
Earlier normal term birth may be a characteristic considered by researchers, clinicians, and parents to help identify children who may be at risk for poorer school performance.
Comments
Academic Achievement and Possible Anesthetic Contribution
To the Editor: At a time when 33% of US fourth graders read below the basic level (1), Noble, et al report third grade reading and math scores are affected by how "term" students are at birth (2). This information, crucial to educational policy, has implications for the study of neurocognitive and developmental effects ascribed to early anesthetic exposure. Animal studies provide evidence that neurodevelopmental disruptions follow a variety of anesthetic exposures.(3) Most, however, use non-ideal animal models, insufficient controls, and anesthetic drug and oxygen levels beyond clinically relevant parameters. At least one very recent study suggests anesthetic and/or oxidative stress effects on mitochondria induce lipid peroxidation, neuroapoptosis, and behavioral changes that are mitigated by experimental intracellular and intra-mitochondrial antioxidant administration (4). This suggests oxygen effects may be as relevant as anesthetic exposure in producing molecular, cellular, and neurodevelopmental harm in animal models (5). Human studies are less conclusive. Extant database analyses suggest anesthetic-related neurotoxicity (6-8) . Multiple anesthetic exposures but not single exposures may correlate with childhood learning disabilities years later (9). Clearly, how to relate such findings to children who require general anesthesia for all forms of surgery is an open question. What is certain is that pediatric anesthesia involves normobaric hyperoxic exposures of varying intensity and duration and that the contribution of hyperoxia during anesthesia is under investigated. In this context, Noble, et al are encouraged to re-visit their database to seek evidence of oxygen exposure with and without anesthesia. Perhaps their large database, which yields a clear connection between gestational age and neurocognitive performance, can also help address the vexing question of whether measurable harm follows general anesthesia with or without normobaric hyperoxia. Collaboration among anesthesiologists, developmental pediatricians, and a funding source such as SmartTots? that focuses on the larger picture may truly help improve the lives and academic performance of our nation's children.
Jamie Wingate, MD Vincent Kopp, MD 1. http://nationsreportcard.gov/reading_2011/nat_g4.asp?tab_id=tab2&subtab_id=Tab_1, accessed 9.11.12 2. Noble KG, Fifer WP, Rauh VA, Nomura Y, Andrews HF. Academic Achievement Varies With Gestational Age Among Children Born at Term. Pediatrics. 2012;130(2):257-264 3. Lei X, Guo O, Zhang J. Mechanistic insights into neurotoxicity induced by anesthetics in the developing brain. Int. J. Mol. Sci. 2010;13:6772-6799 4. Boscolo A, Starr JA, Sanchez V, Lunardi N, DiGruccio MR, Ori C, Erisir A, Trimmer P, Bennett J, Jevtovic-Todorovic V. The abolishment of anesthesia-induced cognitive impairment by timely protection of mitochondria in the developing rat brain: the importance of free oxygen radicals and mitochondrial integrity. Neurobiology of Disease. 2012;45:1031-1041 5. Sifringer M, Bendix I, B?rner C, Endesfelder S, vonHaefen C, Kalb A, Holifanjaniana, Prager S, Schlager GW, Keller M, Jacotot E, Felderhoff- Mueser U. Prevention of neonatal oxygen induced brain damage by reduction of intrinsic apoptosis. Cell Death and Disease. 2012; 3, e250; doi:10.1038/cddis.2011.133 6. Block RI. Thomas JJ, Bayman EO, Choi JY, Kimble KK, Todd MM. Are anesthesia and surgery during infancy associated with altered academic performance during childhood? Pediatrics. 2012;117(3):494-503 7. Wilder RT, Flick RP, Sprung J, Katusic SK, Bargaresi WJ, Mickelson C, Gleich SJ, Schroeder DR, Weaver AL, Warner DO. Early exposure to anesthesia and learning disabilities in a population-based birth cohort. Anesthesiology 2009; 110:796-804 8. Kalkman CJ, Peelen L, Moons KG, Veenhuizen M, Bruens M, Sinnema G, de Jong TP. Behavior and development in children and age at the time of first anesthetic exposure. Anesthesiology. 2009;110:805-812 9. Flick RP, Katusic SK, Colligan RC, Wilder RT, Voigt RG, Olson MD, Sprung J, Weaver A, Schroeder DR, Warner DO. Cognitive and behavioral outcomes after early exposure to anesthesia and surgery. Pediatrics. 2011;128(5):e1053-e1061
Conflict of Interest:
None declared