Dataset of B-vitamins and selected one-carbon and sulfur-containing metabolites in maternal venous and paired umbilical venous and arterial plasma at elective caesarean delivery.

This article describes a dataset of B-vitamins and selected one-carbon and sulfur-containing metabolites measured in maternal venous plasma and paired umbilical venous and umbilical arterial plasma collected at delivery from pregnancies completed by elective caesarean section. Maternal venous blood was collected into lithium-heparin tubes during preoperative preparation before peripheral cannula insertion, immediately placed in an ice/water bath, and processed within 60 min. Umbilical venous and umbilical arterial blood were collected at delivery and handled using the same pre-analytical protocol. Plasma samples were stored frozen at -80°C until analysis. The dataset is organized as a sample-level spreadsheet and contains 394 sample rows from 130 Family ID values, including 130 maternal venous (MV), 132 umbilical venous (UV), and 132 umbilical arterial (UA) samples. Recorded variables include sample identifiers, maternal age, haemolysis index, icteric index, and plasma concentrations of methionine, total homocysteine, total cysteine, lanthionine, cystathionine, hypotaurine, taurine, S-sulfocysteine, thiosulfate, total γ-glutamylcysteine, total cysteinylglycine, total glutathione, total vitamin B12, active vitamin B12, methylmalonic acid, folate, glycine, serine, choline, betaine, dimethylglycine, and sarcosine. The spreadsheet structure supports paired maternal-foetal comparisons and foetal venous-arterial comparisons. It also preserves coding for incomplete and censored observations, and threshold-coded values above the reporting range. The dataset is deposited in Mendeley Data under DOI 10.17632/8pp94xm46j.2, with the current public record. These data may be reused in perinatal metabolism research, sulfur metabolism, one-carbon metabolism, vitamin status studies, and secondary analyses of pre-analytical sample quality.