Prediction of preterm delivery using levels of vascular endothelial growth factor and leptin in amniotic fluid from the second trimester.

Abstract

Impaired angiogenesis of the developing placenta in the early pregnancy is one etiology of preterm delivery. Vascular endothelial growth factor (VEGF) is a key regulator of normal angiogenesis. Leptin stimulates other angiogenic factors, including VEGF. In this study, we aimed to investigate whether levels of VEGF and leptin in amniotic fluid during the second trimester could serve as markers for preterm delivery. This study was conducted on second trimester amniotic fluid samples obtained from women undergoing genetic amniocentesis at 16-20 weeks of gestation. VEGF and leptin levels were measured by enzyme-linked immunosorbent assay in every case of delivery at <37 weeks' gestation (n = 36) and in 36 matched controls who delivered at ≥ 37 weeks' gestation. Amniotic fluid VEGF levels in the preterm group (32.24 ± 4.87 pg/ml) were significantly higher than those in the control group (23.49 ± 2.09 pg/ml) (p < 0.05). Leptin levels in the amniotic fluid were higher in the preterm group (6.64 ± 0.68 ng/ml) compared to the control group (5.35 ± 0.59 ng/ml), but this difference was not significant. Amniotic fluid VEGF and leptin levels were highest in women with placenta previa and were lowest in women with intrauterine growth retardation and pregnancy-induced hypertension. These results show that amniotic fluid VEGF levels in the second trimester are more predictive of preterm delivery than leptin levels. This study also demonstrates that VEGF levels vary depending on the cause of preterm delivery.