Decreased amniotic fluid leptin levels in the second trimester in Down's syndrome.

Objective: To investigate a possible role of leptin contributing to the pathophysiology of Down's syndrome by assessing amniotic fluid leptin levels in the 2nd trimester of normal pregnancy and pregnancy complicated by Down's syndrome.

Methods: We retrospectively assessed leptin levels of 2nd trimester amniotic fluid from 15 pregnancies diagnosed with Down's syndrome and 15 matched unaffected singleton pregnancies (controls). All amniotic fluid samples were obtained from women undergoing genetic amniocentesis at 16-20 weeks of gestation. Leptin levels were measured by enzyme-linked immunosorbent assay.

Results: Amniotic fluid leptin levels were significantly decreased in the Down's syndrome group (3.26 +/- 2.36 ng/ml) compared to the controls (8.26 +/- 9.11 ng/ml, p < 0.05).

Conclusion: This study showed significantly decreased leptin levels in the 2nd trimester amniotic fluid of fetuses with Down's syndrome. This result suggests a possible role of leptin in the pathophysiology of Down's syndrome during the fetal period.