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

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Detection of endometrial and subendometrial vasculature on the day of embryo transfer and prediction of pregnancy during fresh in vitro fertilization cycles.

OBJECTIVES: Successful implantation depends on interaction between a blastocyst and a receptive endometrium. Endometrial vasculature is important in the early endometrial response to blastocyst implantation, and vascular changes can affect uterine receptivity. This study aims to investigate whether vascular parameters measured using three-dimensional power Doppler ultrasound (3D PD-US) could predict pregnancy following fresh in vitro fertilization and embryo transfer (IVF-ET) using a gonadotropin releasing hormone (GnRH) agonist long protocol. MATERIALS AND METHODS: This prospective observational study enrolled 236 nulliparous women who underwent a first IVF-ET using a GnRH long protocol with stimulation by recombinant FSH (rFSH) from May 2009 to April 2012. After excluding two cases of tubal pregnancy, 234 women were in either a pregnant group (n = 113) or a nonpregnant group (n = 121). Color Doppler ultrasound and 3D PD-US examinations were performed on the day of embryo transfer. Main outcomes were pulsatility index (PI), resistance index (RI), systolic/diastolic ratio (S/D) of the uterine artery, vascularization index (VI), flow index (FI), and vascularization flow index (VFI) of the endometrium and subendometrial region. Measurements were analyzed relative to IVF-ET outcome (pregnant vs. nonpregnant). RESULTS: No significant differences were observed in patient age, infertility duration, body mass index (BMI), basal FSH levels, number of retrieved oocytes or good quality embryos, or endometrial thickness or volume between the two groups. The pregnant group had higher endometrial VI, FI, and VFI scores than the nonpregnant group (p = 0.001, p = 0.000, p = 0.021, respectively). By contrast, neither subendometrial region VI, FI, and VFI scores (p = 0.770, p = 0.252, p = 0.451), nor uterine artery PI, RI, or S/D scores (p = 0.256, p = 0.527, p = 0.365) differed between groups. Cut-off values of endometrial VI, FI, and VFI scores were 0.95, 12.94, and 0.15 for pregnancy achievement. CONCLUSION: Three dimensional PD-US was a useful and effective method for assessing endometrial blood flow in IVF cycles. Good endometrial blood flow on the day of embryo transfer might be associated with high pregnancy success with a GnRH long protocol, because this is indicative of endometrial receptivity in fresh IVF cycles.