Relationship between placental oxygen transport, fetal birth weight, and umbilical cord transcriptome in monochorionic twins

Objective To explore the relationship between placental oxygen transport on MRI and fetal birth weight, and to identify associated transcriptional pathways. Study Design We conducted a prospective cohort study of six monochorionic twin pairs. For each pair, the twin with the higher placental oxygen time-to-plateau (TTP) was designated as Group A and the co-twin with the lower TTP as Group B. RNA sequencing of cord blood was performed to assess differential gene expression. Analyses were performed using paired methods to account for within-pair comparisons. Results On descriptive analysis, higher TTP twins (Group A) had lower mean birth weight than their lower TTP co-twins (Group B) (2121 ± 256 g vs 2397 ± 283 g), but this difference was not statistically significant on paired analysis ( p = 0.51). TTP values were also not significantly different within pairs ( p = 0.17). Across all twins, higher TTP was associated with lower birth weight ( p = 0.02). No differentially expressed genes or pathways were identified. Conclusion In this cohort of monochorionic twin pairs, the twin with slower placental oxygen transport tended to have lower birth compared with its co-twin, although this difference was not statistically significant on paired analysis. Higher TTP was correlated with lower birth weight across twins, but no transcriptomic differences were identified. Larger paired datasets are needed to further explore these associations.