Journal of Gynecology and Reproductive Health

Perinatal Leucovorin Offers a Precision Folate Strategy for at Risk Pregnancies

Abstract

George Ayoub

Autism spectrum disorder (ASD) arises from converging genetic, immune, and metabolic perturbations, and current medical treatments for core symptoms remain both limited and largely postnatal. Folate receptor�??alpha autoantibodies (FRAA) and folate�??pathway polymorphisms create cerebral folate deficiency despite adequate systemic folate, and FRAA are enriched in ASD children and their mothers, defining a mechanistically coherent, testable risk subgroup. Randomized trials in ASD children demonstrate that folinic acid (leucovorin), a reduced and bioactive folate that bypasses FRAA�??blocked folate receptor alpha via alternative transporters, improves communication and global symptom scores, with greatest efficacy at younger ages, and it has a favorable safety profile. Translating this finding upstream, a pilot randomized trial in FRAA�??positive pregnancies found that perinatal leucovorin, compared with standard folic acid, was associated with markedly lower ASD incidence, lower ADOS�??2 scores, and higher Bayley�??4 cognitive indices in offspring, while a case series of two FRAA�??positive mothers with prior neurodivergent children reported neurotypical development to age three after preconception and gestational leucovorin. Additional case series in women with MTHFR polymorphisms and infertility suggest that replacing folic acid with reduced folates can restore fertility without increasing total folate dose, underscoring folate form as a modifiable determinant of reproductive and neurodevelopmental outcome. In parallel, preclinical and epidemiologic data raise concern that high�??dose synthetic folic acid remains unmetabolized and may perturb neurodevelopmental trajectories in susceptible subgroups. Together, these converging lines of evidence support a precision perinatal folate paradigm in which leucovorin replaces folic acid for FRAA�??positive and folate�??pathway impaired women, warranting systematic screening and multicenter trials to test leucovorin as a viable prenatal strategy for reducing ASD incidence. 

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