The maternal serum metabolome by multisegment injection-capillary electrophoresis-mass spectrometry: a high-throughput platform and standardized data workflow for large-scale epidemiological studies

A standardized protocol and data workflow for high-throughput analysis of the maternal serum metabolome is outlined. It uses multisegment injection-capillary electrophoresis-mass spectrometry and is applied to a multi-ethnic cohort of pregnant women. A standardized data workflow is described for large-scale serum metabolomic studies using multisegment injection-capillary electrophoresis-mass spectrometry. Multiplexed separations increase throughput (<4 min/sample) for quantitative determination of 66 polar/ionic metabolites in serum filtrates consistently detected (coefficient of variance (CV) <30%) with high frequency (>75%) from a multi-ethnic cohort of pregnant women (n = 1,004). We outline a validated protocol implemented in four batches over a 7-month period that includes details on preventive maintenance, sample workup, data preprocessing and metabolite authentication. We achieve stringent quality control (QC) and robust batch correction of long-term signal drift with good mutual agreement for a wide range of metabolites, including serum glucose as compared to a clinical chemistry analyzer (mean bias = 11%, n = 668). Control charts for a recovery standard (mean CV = 12%, n = 2,412) and serum metabolites in QC samples (median CV = 13%, n = 202) demonstrate acceptable intermediate precision with a median intraclass coefficient of 0.87. We also report reference intervals for 53 serum metabolites from a diverse population of women in their second trimester of pregnancy.

Automated summary

This study outlines a standardized protocol and data workflow for high-throughput analysis of the maternal serum metabolome, which is applied to a multi-ethnic cohort of pregnant women. The method uses multisegment injection-capillary electrophoresis-mass spectrometry with stringent quality control measures to detect and quantify multiple metabolites in serum with high accuracy and efficiency. By implementing this validated protocol, the study achieves robust batch correction for long-term signal drift and establishes reference intervals for serum metabolites in a diverse population of pregnant women in their second trimester.