Losh, who directs Northwestern’s Neurodevelopmental Disabilities Laboratory, warned that the findings from twin research might not prolong to singletons, as the prenatal and perinatal conditions for singletons and twins vary in important ways.. Birth weight is important in autism spectrum disorder Brand-new research suggests birth weight is important in autism spectrum disorderAlthough the genetic basis of autism is currently well established, an evergrowing body of research also shows that environmental factors may are likely involved in this critical developmental disorder affecting nearly 1 in 100 children.Total operating expenses increased 46 percent, or $747 million, to $2.4 billion due primarily to the inclusion of operating expenses linked to the merger with Hewitt, an estimated $102 million unfavorable effect from forex translation and a $62 million upsurge in intangible asset amortization expense, partially offset by benefits linked to the restructuring programs and a $17 million decrease in restructuring related costs.