Adiponectin concentration in mid-trimester amniotic fluid varies with the α-amylase level and maternal and neonatal outcomes.

OBJECTIVE: Factors influencing intraamniotic adiponectin levels and their functional significance remain incompletely elucidated. We prospectively measured adiponectin in amniotic fluid and identified its associations with maternal parameters, mediators in amniotic fluid and pregnancy outcomes.

STUDY DESIGN: Mid-trimester amniotic fluid from 571 women was tested for adiponectin, interleukin (IL)-6, IL-8 and α-amylase by enzyme-linked immunosorbant assay (ELISA), after which clinical data were obtained. Correlations between adiponectin and clinical or laboratory variables were analyzed by the Kruskal-Wallis, Mann-Whitney and Spearman rank correlation tests.

RESULTS: As compared to median levels in 462 women with a term delivery (7.8 ng/mL), adiponectin was elevated in 14 women who subsequently developed preterm premature rupture of membranes (pPROM) (17.3 ng/mL) and 24 women with an iatrogenic preterm birth (IPTB) (13.9 ng/mL) (P=0.0003), but not in 30 women who subsequently had a spontaneous preterm birth with intact membranes (8.1 ng/mL) (P>0.05). Median adiponectin was also elevated in 13 women whose babies developed fetal growth restriction (FGR) (20.6 ng/mL) (P=0.0055) and in 22 women whose babies had respiratory distress syndrome (RDS) (23.0 ng/mL) (P<0.0001). The adiponectin concentration was positively correlated with amylase (P=0.0089) and inversely correlated with maternal body mass index (P=0.0045).

CONCLUSION: Adiponectin is a component of mid-trimester amniotic fluid and its concentration varies with maternal body mass index and subsequent development of pPROM, IPTB, FGR and RDS.