Maternal Serum Vitamin B12 during Pregnancy and Offspring Autism Spectrum Disorder.

Researchers studied over 1,500 Finnish children with autism and compared them to children without autism. They found that mothers with very high vitamin B12 levels during early pregnancy had a higher chance of having a child with autism. However, this link was only seen for one type of autism, not others like Asperger's syndrome.

This Finnish national birth cohort study examined 1,558 children diagnosed with autism spectrum disorders and matched controls to investigate associations between maternal vitamin B12 levels during early pregnancy and offspring ASD risk. The study found that high maternal vitamin B12 levels (≥81st percentile) during first and early second trimesters were associated with increased risk of childhood autism (adjusted OR 1.59, 95% CI 1.06-2.41). However, no significant associations were found between maternal B12 levels and Asperger's syndrome or pervasive developmental disorder not otherwise specified. These findings suggest potential differential effects of maternal B12 on ASD subtypes.

Findings suggest need for balanced approach to maternal B12 supplementation during pregnancy. Further research needed before clinical recommendations. Healthcare providers should consider individual risk-benefit assessment for B12 supplementation in pregnant women.

Single observational study from one country limits generalizability. Mechanism of association unclear. Cannot establish causation. Potential confounding factors may not be fully controlled. Diagnostic criteria variations across study period not addressed.

This study examined the association between maternal serum vitamin B12 levels during early pregnancy and offspring autism spectrum disorders (ASD) and subtypes. Based on a Finnish national birth cohort, case offspring= 1558) born in 1987-2007 and diagnosed with ASD by 2015 were matched with one control on date of birth, sex and place of birth. Maternal vitamin B12 levels were measured during first and early second trimesters of pregnancy. High maternal vitamin B12 levels (≥81th percentile) was associated with increased risk for offspring childhood autism, adjusted odds ratio, 1.59, 95% confidence interval 1.06-2.41 (= 0.026).

No significant associations were observed between maternal vitamin B12 levels and offspring Asperger's or pervasive developmental disorder/NOS.