sFLT1, PlGF, the sFLT1/PlGF Ratio and Their Association with Pre-Eclampsia in Twin Pregnancies-A Review of the Literature

Twin pregnancies demonstrate a 2-3-fold higher chance of developing PE compared to singletons, and recent evidence has demonstrated that the sFLT1/PIGF ratio is strongly associated with PE, adverse pregnancy outcomes, as well as imminent deliveries due to PE complications. The primary objective of this systematic review was to summarise the available data on the levels of sFLT1, PlGF and their ratios in twin pregnancies and to investigate their association with the development of PE, adverse pregnancy outcomes and the timing of the delivery. A systematic search of Ovid Embase, Web of Science, Science Direct, PubMed, Ovid Medline, Google Scholar and CINAHL was carried out. sFLT1 levels and the sFLT1/PIGF ratio appeared higher in twins compared to singleton pregnancies, especially in the third trimester, while PlGF levels appeared higher up until the third trimester, with their values showing no difference or being even lower than in singletons thereafter. The sFLT1/PIGF ratio has been reported to be an independent marker of adverse outcomes related to pre-eclampsia and is associated with the mean time until delivery in an inverse manner. Further research is required in order to establish the optimal sFLT1/PIGF cut-off values and to stratify the risk of adverse outcomes in twin pregnancies.

Automated summary

Twin pregnancies have a higher risk of developing PE compared to singletons, and the sFLT1/PIGF ratio is strongly associated with PE, adverse pregnancy outcomes, and timing of delivery. This systematic review aimed to summarize the data on sFLT1, PlGF, and their ratios in twin pregnancies and investigate their association with PE development, adverse pregnancy outcomes, and timing of delivery. The review found that sFLT1 levels and the sFLT1/PIGF ratio were higher in twins, especially in the third trimester, while PlGF levels were higher before the third trimester and then showed no difference or were even lower than in singletons. The sFLT1/PIGF ratio is an independent marker of adverse outcomes and is inversely associated with the mean time until delivery. Further research is needed to establish optimal sFLT1/PIGF cut-off values and stratify the risk in twin pregnancies.