The predictive value of the sFlt-1/PlGF ratio on short-term absence of preeclampsia and maternal and fetal or neonatal complications in twin pregnancies

Objective: A sFlt-1/PIGF ratio of <= 38 has been reported to predict the absence of preeclampsia (PE) in singleton pregnancies. We evaluated whether a sFlt-1/PIGF ratio of <= 38 could be used to predict the absence of PE in twin pregnancies and maternal and fetal/neonatal complications. Methods: This is a secondary analysis of a prospective multicenter cohort study that enrolled women with suspected or confirmed PE with the aim of evaluating the use of the sFlt-1, PlGF and their ratio to predict maternal and fetal/neonatal complications. Twin and singleton pregnancies with clinically suspected or con- firmed PE were matched for gestational age and parity. Blood samples were drawn at time of study entry, but serum values of sFlt-1 and PlGF and their ratio were determined postpartum. Results: Twenty-one women with twin and 21 with singleton gestations were included at a median gestational age of 30 weeks. At inclusion PE was diagnosed in 13 twin and 15 singleton pregnancies. In comparison to singleton control pregnancies, twin controls had a significantly higher sFlt-1 (6377 vs. 1732 pg/ml, p = 0.008), a higher sFlt-1/PIGF ratio 26 vs. 3 p = 0.361) and a lower PlGF (228 vs. 440 pg/ml p = 0.479). Compared to singleton preeclamptic pregnancies values of sFlt-1 (9134 vs. 8625 pg/ml) did not differ, whereas values of PlGF (185 vs. 33 pg/ml, p < 0.001) were higher and values of the ratio (49 vs. 158, p = 0.002) were lower in preeclamptic twin pregnancies. All preeclamptic patients with a singleton pregnancy had a ratio > 38, but only 5 of the 13 patients with a preeclamptic twin pregnancy. Conversely, the ratio was <= 38 in 5 of the 6 control singleton, but in only 4 of the 8 control twin pregnancies. When classified according to a ratio <= 38 or > 38 at inclusion, maternal complications occurred more frequently in patients with a ratio > 38 both in singleton and twin pregnancies. In singleton pregnancies fetal/neonatal complications, except one admission to NICU, only occurred in patients with a ratio > 38. In twin pregnancies fetal/neonatal complications occurred equally frequent in women with a ratio <= 38 or > 38. Conclusion: Serum sFlt-1 levels are considerably higher in twin than in singleton control gestations. A sFlt-1/PlGF ratio of <= 38 to predict short-term absence of PE is not applicable to twin pregnancies in predicting either the absence of PE or the absence of adverse pregnancy outcomes.