Previous studies of academic achievement of children with oral clefts have mostly relied on small, clinic-based samples prone to ascertainment bias. In the first study in the United States to use a population-based sample with direct assessment, we evaluated the academic achievement of children with oral clefts relative to their classmates.
Children born with isolated oral clefts in Iowa from 1983 to 2003 were identified from the Iowa Registry for Congenital and Inherited Disorders and matched to unaffected classmates by gender, school/school district, and month and year of birth. Academic achievement was assessed by using standardized tests of academic progress developed by the Iowa Testing Programs. Iowa Testing Programs data were linked to birth certificates for all children. Regression models controlled for household demographic and socioeconomic factors. The analytical sample included 588 children with clefts contributing 3735 child-grade observations and 1874 classmates contributing 13 159 child-grade observations.
Children with oral clefts had lower scores than their classmates across all domains and school levels, with a 5-percentile difference in the overall composite score. Children with clefts were approximately one-half grade level behind their classmates and had higher rates of academic underachievement and use of special education services by 8 percentage points. Group differences were slightly lower but remained large and significant after adjusting for many background characteristics.
Children with oral clefts underperformed across all academic areas and grade levels compared with their classmates. The results support a model of early testing and intervention among affected children to identify and reduce academic deficits.
We read with interest the work of Wehby, et al(1) in the April edition of this journal. In this impressive study comparing the academic achievement of 588 children with oral clefts with 1874 matched classmates using the Iowa Registry for Congenital and Inherited Disorders, there was a significant decrease in academic achievement across all domains and with all types of oral clefts. The authors briefly mention hypotheses for the lower academic achievement, including possible differences in brain morphology, prenatal factors such as maternal nutrition, and factors related to the cleft itself such as speech/language impairment, social stigma, or anesthetic exposure.
We propose that the primary reason for learning impairment in children with oral clefts of all types is most likely related to repeated exposure to anesthetic agents. Typically, initial repair of a cleft lip occurs at age 3 months, followed by palate repair at 6 months. Revision is sometimes necessary, leading to several anesthetic exposures in many children. In this study, the authors were unable to control for confounding factors such as number of surgeries and exposure to anesthetic agents. It has been previously shown that multiple exposures to anesthetic agents prior to age 2 is associated with an increase in learning disabilities(2). A meta-analysis of current studies suggests a modestly elevated risk of adverse behavioral or developmental outcomes in children who were exposed to anesthesia and surgery during early childhood(3).
Although isolated cleft palate (CP) has a well-known association with syndromes and learning disabilities, isolated cleft lip (CL) and cleft lip and palate (CLP) seem to have a mechanical pathophysiology without the same associations. The current study refutes this assumption, however, showing no significant difference in academic achievement by cleft type. The finding that CL is associated with decreased academic achievement is particularly significant, as the authors note, since these children are often not followed by Cleft Teams and they may not be identified as early for special education services.
A previous commentary in this journal called on pediatricians to become more aware of the issues related to neurotoxicity from early repeated exposure to anesthetic agents(4), and a recent publication proposes a re-evaluation of the current protocols for timing and number of surgeries in the treatment of oral clefts(5). Additional rigorous studies are desperately needed in this area. Communication among pediatricians, surgeons, and anesthesiologists about the issue of potential anesthetic neurotoxicity needs to expand, so that appropriate scheduling of surgeries takes place, delaying them until an older age if at all possible.
1 Wehby GL, Collet B, Barron S, Romitti PA, Ansley TN, Speltz M: Academic Achievement of Children and Adolescents With Oral Clefts. Pediatrics 2014; 133:785-792.
2 Flick. Cognitive and Behavioral outcomes after early exposure to anesthesia and surgery. Pediatrics. 2011;128(5). e1053.
3 DiMaggio C, Sun LS, Ing C, Li G. Pediatric anesthesia and neurodevelopmental impairments: a Bayesian meta-analysis. J Neurosurg Anesthesiol. 2012 Oct;24(4):376-81.
4 Williams RK. The Pediatrician and Anesthesia Neurotoxicity Pediatrics 2011;128;e1268.
5 Laub DR and Williams RK. Neonatal Anesthesia Neurotoxicity: a Review for Cleft and Craniofacial Surgeons. Cleft Palate Craniofacial J in press.
Conflict of Interest:
None declared