Evidence of perinatal complications associated with autism 1. Bilder D, Pinborough-Zimmerman J, Miller J, McMahon W. Prenatal, perinatal, and neonatal factors associated with autism spectrum disorders.Pediatrics. 2009 May;123(5):1293-300. "Children with an ASD were more likely to have a breech presentation . . .   and be born by primary cesarean delivery . . . The significance of primary cesarean delivery was lost when excluding those children presenting breech (which is an indication for performing a cesarean delivery)." 2.  van Handel M, Swaab H, de Vries LS, Jongmans MJ.Long-term cognitive and behavioral consequences of neonatal encephalopathy following perinatal asphyxia: a review. Eur J Pediatr. 2007 Jul;166(7):645-54.. "Most outcome studies have focused on neurological functioning and severe deficits in young children (<4 years).  In general, very few children with mild encephalopathy show neurological impairments or have developed severe mental or motor retardation at preschool age. ... Only a few studies looked at the behavioral consequences of NE.  Those studies found elevated rates of hyperactivity and autism in children with moderate NE." 3.  Kolevzon A, Gross R, Reichenberg A.Prenatal and perinatal risk factors for autism: a review and integration of findings. Arch Pediatr Adolesc Med. 2007 Apr; 161(4):326-33. "According to our review, 3 parental characteristics and 2 obstetric conditions emerge as potential risk factors for autism: namely, paternal age, maternal age, maternal immigration, growth restriction, and newborn hypoxia. In analyses that adjusted for confounding variables, these factors usually remained statistically significant." 4.  Maimburg RD, Vaeth M. Perinatal risk factors and infantile autism. Acta Psychiatr Scand. 2006 Oct;114(4):257-64. " We also found strong associations between children with infantile autism and mothers with foreign citizenship, children with congenital malformations and children who needed treatment at Neonatal Intensive Care Unit (NICU) after birth. When the caesarean sections were categorized into scheduled and unscheduled procedures, we found only scheduled caesarean sections to be associated with infantile autism." 5.  Badawi N et al. Autism following a history of newborn encephalopathy: more than a coincidence? Dev Med Child Neurol. 2006 Feb;48(2):85-9. "... in a population-based study of moderate and severe term newborn encephalopathy (NE) in Western Australia ...infants with NE were 5.9 (95% CI 2.0–16.9) times more likely to be diagnosed with an ASD than controls... this was not an expected association at the outset of the study" 6. Sugie Y et al. Neonatal factors in infants with Autistic Disorder and typically developing infants. Autism. 2005 Dec;9(5):487-94. "Frequent neonatal complications included hyperbilirubinemia, history of phototherapy, premature birth (less than 37 weeks), asphyxia, post-term birth of 42 weeks or longer, fetal distress, and complications of respiratory distress." 7. Larsson HJ et al. Risk factors for autism: perinatal factors, parental psychiatric history, and socioeconomic status. Am J Epidemiol. 2005;161:916-25. "In the unadjusted analyses, breech presentation, lowApgar score (less than or equal 7) at 5 minutes, low birth weight (less than or equal 2,500 g), gestational age at birth of less than 35 weeks, and being small for gestational age were associated with a statistically significantly increased risk of autism..." 8. Gillberg C, Cederlund M. Asperger syndrome: familial and pre- and perinatal factors. J Autism Dev Disord. 2005 Apr;35(2):159-66. "Five children had had an Apgar score of 6 or under at 1, 5 , or 10 minutes, and 3 of these had scores of 1 or 2 (i.e., they had severe postnatal asphyxia). ... Of the 100 individuals, 58 had one or more remarks in their birth- or perinatal records about a serious problem in the peri-/neonatal period." 9.  Cederlund M, Gillberg C.  One hundred males with Asperger syndrome: a clinical study of background and associated factors. Dev Med Child Neurol. 2004 Oct;46(10):652-60. For 58 of 99 children, some kind of abnormality was noted in their neonatal record. ... Twenty-two had had hyperbilirubinemia (plasma bilirubin more than 200μmol/l), ... Hyperbilirubinemia occurs in about 10% of newborn infants...  Forty-five of 92 children (49%) for whom fairly detailed data about early language development were available, clearly did not have normal language development at 2 years of age. It cannot be concluded that the remainder had normal language development. 10. Glasson EJ et al. Perinatal factors and the development of autism: a population study. Arch Gen Psychiatry. 2004 Jun;61(6):618-27. "Cases were more likely to have experienced fetal distress during labor (OR, 1.64; 95% CI, 1.15-2.34). Apgar scores calculated at 1 minute showed that significantly more cases achieved a score of 6 or less (54 [19.5%] of 277 cases with data recorded since 1991..." "[12.9%] of 512 control subjects with data recorded since 1991)(OR, 1.6; 95% CI, 1.1-2.4), and cases were more likely to have taken more than 1 minute before the onset of spontaneous respiration (OR, 1.4; 95% CI, 1.0-1.9)." 11. Wilkerson DS et al. Perinatal complications as predictors of infantile autism.  Int J Neurosci. 2002 Sep;112(9):1085-98. "… 5 items were found to significantly predict group membership (prescriptions taken during pregnancy, length of labor, viral infection, abnormal presentation at delivery, and low birth weight)." 12. Hultman CM et al. Perinatal risk factors for infantile autism.   Epidemiology. 2002 Jul;13(4):417-23. "The risk of autism was associated with daily smoking in early pregnancy (OR = 1.4; CI = 1.1-1.8), maternal birth outside Europe and North America (OR = 3.0; CI = 1.7-5.2), cesarean delivery (OR = 1.6; CI = 1.1-2.3), being small for gestational age (SGA; OR = 2.1; CI = 1.1-3.9), a 5-minute Apgar score below 7 (OR = 3.2, CI = 1.2-8.2), and congenital malformations (OR = 1.8, CI = 1.1-3.1)."   Note: The OR (odds ratio) was greatest for 5-min Apgar score below 7." 13. Zwaigenbaum L et al. Pregnancy and birth complications in autism and liability to the broader autism phenotype.  J Am Acad Child Adolesc Psychiatry 2002 May; 41(5):572-9 "Children with autism spectrum disorders have lower optimality (higher rates of complications) than unaffected siblings…" 14. Greenberg DA et al. Excess of twins among affected sibling pairs with autism: implications for the etiology of autism.  Am J Hum Genet 2001 Nov;69(5):1062-7 "In a sample of families selected because each had exactly two affected sibs, we observed a remarkably high proportion of affected twin pairs, both MZ and DZ…" 15. Bodier C et al. Autisme et pathologies associées. Étude clinique de 295 cas de troubles envahissants du developpment. [Autism and associated pathologies. Clinical study of 295 cases involving development disorders]  Presse Médicale 2001 Sep 1; 30(24 Pt 1):1199-203. French. "Among the children with a serious medical condition, 34.4% also had ante- or perinatal antecedents. Among the 33% without any medical factor, 77% also had ante- or perinatal antecedents." 16. Juul-Dam N et al. Prenatal, perinatal, and neonatal factors in autism, pervasive developmental disorder-not otherwise specified, and the general population.    Pediatrics. 2001 Apr;107(4):E63. "… specific complications that carried the highest risk of autism and PDD- NOS represented various forms of pathologic processes with no presently apparent unifying feature." 17. Matsuishi T et al. Brief report: incidence of and risk factors for autistic disorder in neonatal intensive care unit survivors.   J Autism Dev Disord. 1999 Apr;29(2): 161-6 "AD was identified in 18 of the 5,271 children and the incidence was 34 per 10,000 (0.34%). This value was more than twice the highest prevalence value previously reported in Japan. Children with AD had a significantly higher history of the meconium aspiration syndrome (p = .0010) than the controls. Autistic patients had different risk factors than CP."  Note: CP (cerebral palsy) occurred in 57 of the 5,271 children." 18. Bolton PF et al. Obstetric complications in autism: consequences or causes of the condition? J Am Acad Child Adolesc Psychiatry. 1997 Feb;36(2):272-81 "…[obstetric] optimality score (OS), were compared in two groups: 78 families containing an autistic proband (ICD-10 criteria) and 27 families containing a down syndrome (DS) proband…  RESULTS: Autistic and DS probands had a significantly elevated OS compared with unaffected siblings, regardless of birth order position. The elevation was mainly due to an increase in mild as opposed to severe obstetric adversities." 19. Ghaziuddin M et al. Obstetric factors in Asperger syndrome: comparison with high-functioning autism.  J Intellect Disabil Res. 1995 Dec;39 ( Pt 6):538-43. "Males with AS showed a trend toward lower Apgar scores at one minute …" 20. Lord C et al. Pre- and perinatal factors in high-functioning females and males with autism.  J Autism Dev Disord. 1991 Jun;21(2):197-209. "These data provide slight support for the contribution of nonspecific pre- and perinatal factors to other etiological bases of autism." 21. Steffenburg S et al. A twin study of autism in Denmark, Finland, Iceland, Norway and Sweden.  J Child Psychol Psychiatry. 1989 May;30(3):405-16. "In most of the pairs discordant for autism, the autistic twin had more perinatal stress." 22. Levy S et al. A comparison of obstetrical records of autistic and nonautistic referrals for psychoeducational evaluations.  J Autism Dev Disord. 1988 Dec;18(4): 573-81. "Abnormal presentation at birth is the only factor that occurred more frequently for the autistic sample…" 23. Lobascher ME et al. Childhood autism: an investigation of aetiological factors in twenty-five cases. Br J Psychiatry. 1970 Nov;117(540):525-9. "There were more complications of labour in the experimental group than the controls (p=0.001) ...Abnormal conditions of the child noted at delivery occurred significantly more frequently in the experimental group, e.g. difficulty with resuscitation, cord around neck, fractured skull, cyanosis, head moulding, bruising, jaundice (p<0.0004)."