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Updated: May 12, 2026

Rapid and Efficient Spatiotemporal Monitoring of Normal and Aberrant Cytosine Methylation within Intact Zebrafish Embryos
Published on: August 18, 2022
Methylation metabolites in amniotic fluid depend on gestational age
Apolline Imbard1, Henk J Blom, Dimitri Schlemmer
1Biochemistry Hormonology Laboratory, AP-HP Hôpital Robert Debré, Paris, France. apolline.imbard@rdb.aphp.fr
Amniotic fluid analysis reveals key methylation metabolite changes during pregnancy. Methionine decreases, while the S-adenosyl-L-methionine/S-adenosyl-L-homocysteine ratio increases, indicating growing fetal methylation capacity.
Area of Science:
- Biochemistry
- Developmental Biology
- Metabolomics
Background:
- Methylation metabolism is crucial for fetal development.
- Normative data for amniotic fluid (AF) methylation metabolites across gestation is limited.
- Understanding these metabolites aids in assessing fetal health and development.
Purpose of the Study:
- To establish reference values for 14 key methylation intermediates in amniotic fluid.
- To analyze the relationship between these metabolites and gestational age.
- To investigate the role of specific metabolites in fetal methylation processes.
Main Methods:
- Retrospective analysis of 268 amniotic fluid samples (14-39 weeks gestation).
- Quantification of methionine-cycle intermediates and methyl donors/acceptors using liquid chromatography-tandem mass spectrometry.
- Determination of reference ranges for each metabolite based on gestational age.
Main Results:
- Reference ranges for 14 amniotic fluid metabolites were established.
- Significant correlations were found between linked metabolites and between homocysteine and betaine.
- Methionine levels decreased significantly with advancing gestational age.
Conclusions:
- The S-adenosyl-L-methionine/S-adenosyl-L-homocysteine ratio increases exponentially after 25 weeks, suggesting enhanced fetal methylation capacity.
- Betaine may serve as a fetal methyl donor, supported by its inverse correlation with homocysteine.
- These findings provide crucial normative data for methylation metabolites in amniotic fluid during pregnancy.
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