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

The association between selected mid-trimester amniotic fluid candidate proteins and spontaneous preterm delivery

Objective: The aim of this study was to explore inflammatory response and identify early potential biomarkers in mid-trimester amniotic fluid associated with subsequent spontaneous preterm delivery (PTD).Methods: A cohort study was performed at Sahlgrenska University Hospital/Östra, Gothenburg, Sweden, between 2008 and 2010. Amniotic fluid was collected from consecutive women undergoing mid-trimester transabdominal genetic amniocentesis at 14-19 gestational weeks. Clinical data and delivery outcome variables were obtained from medical records. The analysis included 19 women with spontaneous PTD and 118 women who delivered at term. A panel of 26 candidate proteins was analyzed using Luminex xMAP technology. Candidate protein concentrations were analyzed with ANCOVA and adjusted for plate effects.Results: The median gestational age at delivery was 35 + 3 weeks in women with spontaneous PTD and 40 + 0 weeks in women who delivered at term. Nominally significantly lower amniotic fluid levels of adiponectin (PTD: median 130,695 pg/mL (IQR 71,852-199,414) vs term: median 185,329 pg/mL (IQR (135,815-290,532)), granulocyte-macrophage colony stimulating factor (PTD: median 137 pg/mL (IQR 74-156) vs term: median 176 pg/mL (IQR 111-262)), and macrophage migration inhibitory factor (PTD: median 3025 pg/mL (IQR 1885-3891) vs term: median 3400 pg/mL (IQR 2181-5231)) were observed in the spontaneous PTD group, compared with the term delivery group, after adjusting for plate effects. No significant differences remained after Bonferroni correction for multiple comparisons.Conclusions: Our results are important in the process of determining the etiology behind spontaneous PTD but due to the non-significance after Bonferroni correction, the results should be interpreted with caution. Further analyses of larger sample size will be required to determine whether these results are cogent and to examine whether microbial invasion of the amniotic cavity or intra-amniotic inflammation occurs in asymptomatic women in the mid-trimester with subsequent spontaneous PTD.

The follicle-stimulating hormone receptor Asn680Ser polymorphism is associated with preterm birth in Hispanic women

OBJECTIVE

Recently, a study based on the analysis of accelerated evolution of related genes at birth identified the follicle-stimulating hormone receptor (FSHR) as a possible candidate for the development of preterm delivery. Additionally, FSHR expression has been described in extragonadal tissue including the placenta. Therefore, the aim of the present study was to determine the association between the N680S polymorphism of the follicle-stimulating hormone receptor and preterm birth in a population of Hispanic women.

METHODS

Placenta samples were obtained from 64 women who had preterm births and 54 control cases. DNA was extracted and genotyped for the N680S FSHR gene polymorphism by polymerase chain reaction-restriction fragment length polymorphism. The χ² test and t-test were used to calculate statistical significance.

RESULTS

Statistically significant differences in genotype frequencies for the N680S polymorphism were observed between preterm and term groups (p = .04). Based on the Akaike information criterion values, the dominant model showed that the NN genotype had a significantly increased risk of preterm birth compared with the SS + NS genotype (OR 2.52, 95% CI 1.20-5.33, p = .02).

CONCLUSIONS

The results herein suggest that the FSHR polymorphism N680S is significantly associated with preterm birth in the Hispanic population.

Midkine and Pleiotrophin Concentrations in Amniotic Fluid in Healthy and Complicated Pregnancies

Background

Midkine (MDK) and pleiotrophin (PTN) are heparin-binding growth factors that, in rodents, are highly expressed in early life and decrease to undetectable levels by adulthood. The potential roles of MDK and PTN in human growth and development are not completely elucidated.

Method and Findings

To delineate the role of MDK and PTN in human development, we developed high sensitivity assays to measure their concentrations in amniotic fluid (AF) at various gestational ages in both healthy and complicated pregnancies. We found that both of these growth factors could be readily measured in AF and that the concentrations were higher than most cytokines previously reported in AF.

Conclusion

The concentration of MDK but not that of PTN declined with gestational age. Both MDK and PTN concentrations were found to be lower in pregnancies that were complicated by chorioamnionitis at term, raising the possibility that these growth factors might be useful as markers for infection.

Adipokinins in pregnancies at risk of preterm delivery

OBJECTIVE

To compare adipokinins between women experiencing preterm labor (PTL) and prior preterm deliveries (PTD).

STUDY DESIGN

In this prospective observational cohort, 110 women with a singleton <35 weeks at increased risk of PTD were studied. Serum leptin, adiponectin, and resistin were obtained at three times (23-34 weeks, 35-36 weeks, at delivery) and analyzed via enzyme-linked immunosorbent assay. The adipokinins were compared across time and between PTL (n = 59) and prior PTD (n = 51) groups using generalized estimated equation models.

RESULTS

There were no differences in leptin, adiponectin, or resistin levels over the three times between the PTL and PTD groups. There was a trend toward higher leptin levels (p = 0.06 unadjusted analysis, p = 0.09 adjusted analysis) at 23-34 weeks. When stratified by body mass index (BMI), there were differences in leptin (p < 0.001 for BMI < 30; p = 0.77 for BMI ≥ 30) and adiponectin (p = 0.04 for BMI < 30; p = 0.09 for BMI ≥ 30), but not in resistin over the three times between the PTL and prior PTD groups.

CONCLUSION

There were no significant differences in adipokinins in women with PTL and a prior PTD. The trends toward higher leptin levels at 23-34 weeks in women with PTL may represent a compensatory response and require further evaluation in the study of treatments for PTL.