First trimester inhibin-A concentrations and later development of preeclampsia

Serum biomarkers combined with uterine artery Doppler in prediction of preeclampsia

First-trimester screening may be a major advantage over a second-trimester approach since it opens prospects for early and more efficient interventions. The aim of the current study was to evaluate whether the measurement of maternal serum inhibin A, activin A and placental growth factor (PlGF) at three to four months gestation with the second-trimester uterine artery pulsatility index (PI) are useful in predicting preeclampsia in a group of nulliparous women. All the patients also underwent uterine artery Doppler examination to measure the PI at 22–24 weeks gestation. Inhibin A, activin A and PlGF were measured using an ELISA by an examiner who was blinded to the pregnancy outcome. Thirty-eight cases with preeclampsia and 100 controls were analyzed. Second-trimester uterine artery PI and marker levels were expressed as multiples of the median (MoM). The uterine artery PI was increased in pregnancies with preeclampsia compared with controls. In pregnancies that developed preeclampsia, the uterine artery PI was increased (1.61±0.047 vs. 1.02±0.049, P<0.001), as was the level of inhibin A (1.72±0.023 vs. 1.03±0.063, P<0.001) and the level of activin A (1.68±0.38 vs. 1.06±0.42, P<0.001) compared with the controls. In contrast, the level of PlGF was decreased in pregnancies that developed preeclampsia compared with the controls (0.69±0.23 vs. 1.00±0.26, P<0.001). A combination of activin A, PlGF and uterine artery PI gave an AUC of 0.915 (95% CI, 0.812–0.928; P<0.001) with a sensitivity of 91% at a specificity of 82%. In our study, we demonstrated that both serum inhibin A and activin A levels were increased, while the PlGF level was decreased in the early second-trimester in women who developed preeclampsia.

Early Pregnancy Biomarkers in Pre-Eclampsia: A Systematic Review and Meta-Analysis

Pre-eclampsia (PE) complicates 2%–8% of all pregnancies and is an important cause of perinatal morbidity and mortality worldwide. In order to reduce these complications and to develop possible treatment modalities, it is important to identify women at risk of developing PE. The use of biomarkers in early pregnancy would allow appropriate stratification into high and low risk pregnancies for the purpose of defining surveillance in pregnancy and to administer interventions. We used formal methods for a systematic review and meta-analyses to assess the accuracy of all biomarkers that have been evaluated so far during the first and early second trimester of pregnancy to predict PE. We found low predictive values using individual biomarkers which included a disintegrin and metalloprotease 12 (ADAM-12), inhibin-A, pregnancy associated plasma protein A (PAPP-A), placental growth factor (PlGF) and placental protein 13 (PP-13). The pooled sensitivity of all single biomarkers was 0.40 (95% CI 0.39–0.41) at a false positive rate of 10%. The area under the Summary of Receiver Operating Characteristics Curve (SROC) was 0.786 (SE 0.02). When a combination model was used, the predictive value improved to an area under the SROC of 0.893 (SE 0.03). In conclusion, although there are multiple potential biomarkers for PE their efficacy has been inconsistent and comparisons are difficult because of heterogeneity between different studies. Therefore, there is an urgent need for high quality, large-scale multicentre research in biomarkers for PE so that the best predictive marker(s) can be identified in order to improve the management of women destined to develop PE.

Inhibin A, activin A, placental growth factor and uterine artery Doppler pulsatility index in the prediction of pre-eclampsia

OBJECTIVES

To evaluate whether the measurement of maternal serum inhibin A, activin A and placental growth factor (PlGF) at 12 + 0 to 16 + 0 weeks of gestation alone or in combination with second-trimester uterine artery Doppler pulsatility index (PI) is useful in predicting pre-eclampsia.

METHODS

This was a case-control study of pre-eclampsia. From pregnant women attending their first antenatal examination at 12-16 weeks we collected serum samples and stored them at - 80 °C. All patients also underwent uterine artery Doppler examination to measure the PI at 22-24 weeks' gestation. We retrieved for analysis frozen samples from women who then developed pre-eclampsia, as well as three control samples per woman, matched for gestational age and storage time. Inhibin A, activin A and PlGF were measured using an enzyme-linked immunosorbent assay (ELISA) by an examiner who was blinded to the pregnancy outcome.

RESULTS

There were 31 cases with pre-eclampsia and 93 controls. Second-trimester uterine artery PI and marker levels were expressed as multiples of the median (MoM). The uterine artery PI was increased in pregnancies with pre-eclampsia compared with controls (mean ± SD, 1.45 ± 0.31 MoM vs. 1.02 ± 0.25 MoM, P < 0.001), as were the level of inhibin A (mean ± SD, 1.57 ± 0.34 MoM vs. 1.08 ± 0.43 MoM, P < 0.001) and the level of activin A (mean ± SD, 1.68 ± 0.38 MoM vs. 1.06 ± 0.42 MoM, P < 0.001). The level of PlGF was decreased in pre-eclampsia compared with controls (mean ± SD, 0.69 ± 0.23 MoM vs. 1.00 ± 0.26 MoM, P < 0.001). Receiver-operating characteristics curves were analyzed for controls and cases and areas under the curve (AUC) were 0.796 (95% CI, 0.712-0.880, P < 0.001) for inhibin A, 0.823 (95% CI, 0.746-0.899, P < 0.001) for activin A, 0.831 (95% CI, 0.752-0.910, P < 0.001) for PlGF and 0.851 (95% CI, 0.783-0.920, P < 0.001) for uterine artery PI. The combination of activin A, inhibin A and PI using logistic regression analysis yielded an AUC of 0.907 (95% CI, 0.830-0.938, P < 0.001) with a sensitivity of 87% and a specificity of 80%. The combination of activin A, PlGF and PI gave an AUC of 0.925 (95% CI, 0.852-0.978, P < 0.001) with a sensitivity of 90% and a specificity of 80%. Combining all four markers gave an AUC of 0.941 (95% CI, 0.891-0.990, P < 0.001) with a sensitivity of 93% and a specificity of 80%.

CONCLUSION

Early second-trimester serum inhibin A, activin A, PlGF and second-trimester uterine artery Doppler PI may add further information for the prediction of pre-eclampsia. The combination of the three serum markers and uterine artery Doppler PI has the highest prediction value for pre-eclampsia.

Novel biomarkers for predicting preeclampsia

Preeclampsia is a major cause of maternal morbidity and mortality worldwide. Despite decades of research into the condition, the ability of clinicians to predict preeclampsia prior to the onset of symptoms has not improved significantly. In this review, we will examine the pathophysiology underlying preeclampsia and will look at potential biomarkers for early prediction and diagnosis. In addition, we will explore potential future areas of research into the condition.

Serum screening with Down's syndrome markers to predict pre-eclampsia and small for gestational age: systematic review and meta-analysis

Background

Reliable antenatal identification of pre-eclampsia and small for gestational age is crucial to judicious allocation of monitoring resources and use of preventative treatment with the prospect of improving maternal/perinatal outcome. The purpose of this systematic review was to determine the accuracy of five serum analytes used in Down's serum screening for prediction of pre-eclampsia and/or small for gestational age.

Methods

The data sources included Medline, Embase, Cochrane library, Medion (inception to February 2007), hand searching of relevant journals, reference list checking of included articles, contact with experts. Two reviewers independently selected the articles in which the accuracy of an analyte used in Downs's serum screening before the 25^th gestational week was associated with the occurrence of pre-eclampsia and/or small for gestational age without language restrictions. Two authors independently extracted data on study characteristics, quality and results.

Results

Five serum screening markers were evaluated. 44 studies, testing 169,637 pregnant women (4376 pre-eclampsia cases) and 86 studies, testing 382,005 women (20,339 fetal growth restriction cases) met the selection criteria. The results showed low predictive accuracy overall. For pre-eclampsia the best predictor was inhibin A>2.79MoM positive likelihood ratio 19.52 (8.33,45.79) and negative likelihood ratio 0.30 (0.13,0.68) (single study). For small for gestational age it was AFP>2.0MoM to predict birth weight < 10^th centile with birth < 37 weeks positive likelihood ratio 27.96 (8.02,97.48) and negative likelihood ratio 0.78 (0.55,1.11) (single study). A potential clinical application using aspirin as a treatment is given as an example.

There were methodological and reporting limitations in the included studies thus studies were heterogeneous giving pooled results with wide confidence intervals.

Conclusion

Down's serum screening analytes have low predictive accuracy for pre-eclampsia and small for gestational age. They may be a useful means of risk assessment or of use in prediction when combined with other tests.