Preeclampsia (PE) is a major cause of maternal, fetal, and neonatal illness and death, affecting 2–5% of pregnancies. Gut microbiota and their metabolites are increasingly recognized as contributors to PE, but human data on TMAO (a gut-microbe-derived metabolite already linked to cardiovascular disease) in pregnancy was previously limited. This study helps clarify whether TMAO plays a role in triggering PE or in worsening it as it progresses, which could inform future monitoring or intervention strategies.
This prospective nested case-control study (Sep 2017–Dec 2018) at a hospital in Changsha, China, measured plasma TMAO levels in 264 pregnant women (17 with early-onset PE, 49 with late-onset PE, 198 healthy controls) at two time points: the second trimester (15–23 weeks) and at delivery. TMAO levels increased substantially from the second trimester to delivery in most subjects, but levels at these two time points were not strongly correlated. Second-trimester TMAO was not associated with PE risk, but TMAO at the time of delivery was strongly associated with PE, especially early-onset and severe PE.
Huang, X., Li, Z., Gao, Z., Wang, D., Li, X., Li, Y., Mi, C., & Lei, J. (2020). Association between risk of preeclampsia and maternal plasma trimethylamine-N-oxide in second trimester and at the time of delivery. BMC Pregnancy and Childbirth, 20, 302.