Altered amniotic fluid leptin levels in twin-twin transfusion syndrome with concurrent placental insufficiency.

Objective: To measure amniotic fluid leptin levels in fetuses with twin-twin transfusion syndrome (TTTS) with and without placental insufficiency (PI) and determine its usefulness as a biomarker of PI.

Study Design: A retrospective case control study of TTTS stage III patients from 2009 to 2011 was conducted. Cases were pregnancies with PI (TTTS-PI, n = 18) matched by stage, gestational age, and degree of cardiomyopathy to controls without PI (TTTS, n = 26). PI was strictly defined using biometric parameters. Amniotic fluid from recipient twins (RT) was taken during second trimester fetoscopic laser therapy. Leptin concentrations were determined and compared to growth parameters and birth weight.

Results: RT-adjusted leptin was 66% higher in TTTS-PI (p = 0.016) compared to TTTS controls. Cases had significantly higher growth discordance (p = 0.004) and lower RT birth weight (p = 0.041) compared to controls. Significantly higher adjusted leptin levels were observed at birth in the TTTS-PI group when comparing those with SGA donor twins to those of normal weight (p = 0.016).

Conclusion: These data suggest a role for leptin in pregnancies complicated by TTTS with placental insufficiency. However, further studies are needed to define its mechanism and potential role as a biomarker in amniotic fluid for placental pathophysiology.