Differential expression of immune system-related components in midtrimester amniotic fluid from singleton and twin pregnancies.

Overview

OBJECTIVE: We investigated differences between singleton and twin gestations in immune mediators in midtrimester amniotic fluid. STUDY DESIGN: Amniotic fluid from 252 singleton and 46 twin gestations were tested by enzyme-linked immunosorbent assay for interleukin-1beta, interleukin-1 receptor antagonist, interleukin-4, tumor necrosis factor-alpha, nitric oxide, Clara cell protein 16, leptin, and the 70-kDa heat shock protein. A subset of amniotic fluid was also tested for leukemia inhibitory factor, angiogenin, and migration inhibitory factor-related protein 8 and migration inhibitory factor-related protein 14. Data were analyzed by the Mann-Whitney U test and Spearman rank correlation. RESULTS: Median concentrations of interleukin-1beta, tumor necrosis factor-alpha, interleukin-4, Clara cell protein 16, leptin, and angiogenin were increased in amniotic fluid from twins; median levels of the 70-kDa heat shock protein, leukemia inhibitory factor, migration inhibitory factor-related protein 8, and migration inhibitory factor-related protein 14 were highest in amniotic fluid from singletons (P < .001). CONCLUSION: Elevated levels of immune activators may contribute to the increased rate of preterm premature rupture of membranes and spontaneous preterm birth in twin populations.