Introduction: Metabolic analysis has been performed on 5 children who have been diagnosed with autism (developmental delay), and who were born to mothers who used nitrous oxide for pain relief during labour. The analysis showed elevated levels of the methylB12 deficiency markers, HVA, VMA, QA and pyroglutamic acid, supporting the notion that there had been extensive inactivation of the enzyme methionine synthase. The results are consistent with the known ability of nitrous oxide to form NO-Co(III)cobalamin, which subsequently irreversibly inactivates the enzyme methionine synthase. The data contradicts the contention of many obstetricians and maternity staff that Nitrous oxide is harmless to the mother and baby. The findings are consistent with the hypothesis that it is the increased usage of nitrous oxide during labor that is responsible for the 30-fold increase in the rate of autism in the past 30 years. The findings strongly suggest that nitrous oxide should be banned during labor.

Summary: Studies of children with autism who were born to mothers who used nitrous oxide for pain relief during delivery, have shown that the nitrous oxide has inactivated the vitamin B12, and subsequently the presence of inactive vitamin B12 has led to the developmental delay.