Measurement of inhibin A and activin A in pregnancy--possible diagnostic applications

Early detection of preeclampsia using inhibin a and other second-trimester serum markers

OBJECTIVE

The purpose of this study was to determine whether second-trimester maternal serum markers including inhibin A are useful for the detection of preeclampsia.

METHODS

Between January 2005 and March 2009, we analyzed the data of 4,764 subjects who underwent second-trimester multiple-marker screening for Down syndrome. Serum samples were assayed at 15+0 to 20+6 weeks for maternal serum alpha-fetoprotein (MSAFP), human chorionic gonadotrophin (hCG), unconjugated estriol (uE(3)) and inhibin A. We reviewed all medical records retrospectively, and assessed the relationships of several markers with preeclampsia using logistic regression analysis.

RESULTS

The study sample included 41 patients who developed preeclampsia and a control group consisting of the other 4,723 healthy subjects treated between January 2005 and March 2009. There were no significant differences in gestational ages at blood sampling, maternal weights, gravidity and parity between the two groups. However, the mean ages, Apgar scores, gestational age at delivery and neonatal weights were significantly different between the study group and the control group. The levels of markers in the study group were significantly increased compared to the control group, 1.76 ± 2.68 for inhibin A, 1.18 ± 0.69 for MSAFP, and 1.62 ± 1.18 for hCG, but uE(3) did not differ significantly between the two groups. The AUC of inhibin A was 0.715, but the AUC of a three-marker combination model (0.800) was even better. A mid-trimester inhibin A concentration of 1.5 MoM or greater had a sensitivity of 60% and a false-positive rate of 16% for the prediction of preeclampsia. Inhibin A was the best predictor of preeclampsia. Three other markers were reliable predictive markers of preeclampsia.

CONCLUSIONS

Inhibin A and other second-trimester serum markers may be useful for early detection of preeclampsia. Inhibin A was in fact the most important predictable marker among the markers we surveyed. The results of this study support those of previous studies, and provide quantified data elucidating the occurrence of preeclampsia.

First trimester levels of inhibins and activin A in normal and failing pregnancies

OBJECTIVE

Miscarriage is the commonest complication of human pregnancy. We undertook this study to assess whether inhibin A, pro-alphaC inhibin and/or activin A, products of the corpus luteum and placenta, might be useful in either the prediction or diagnosis of miscarriage.

DESIGN

Case-control study.

PATIENTS

Ninety-eight asymptomatic women at 6-13 weeks gestation who subsequently had a miscarriage and 198 gestation-matched women with a normal singleton pregnancy.

MEASUREMENTS

Maternal serum levels of inhibin A, pro-alphaC inhibin, activin A and human chorionic gonadotrophin (hCG) were measured.

RESULTS

Inhibin A, pro-alphaC and hCG, expressed as multiples of the normal median (MoM; +/-95% confidence intervals) in the miscarriage cases were significantly lower than in the viable controls, 0.56 (0.48-0.69) MoM vs. 1.00 (0.98-1.13) MoM, 0.55 (0.51-0.84) MoM vs. 1.0 (0.86-1.22) MoM and 0.34 (0.23-0.36) MoM vs. 1.00 (0.94-1.08) MoM, respectively (P < 0.0001 for all). Of the three analytes, hCG was the most discriminating between cases and controls. Levels of activin A in the miscarriage cases were not significantly different from controls, 0.96 (0.86-1.07) vs. 1.0 (0.95-1.08).

CONCLUSIONS

These data suggest that inhibin A, pro-alphaC inhibin and activin A will not be useful in either the prediction or diagnosis of early pregnancy miscarriage.

Maternal serum inhibin A levels may predict pregnancy outcome in women with threatened abortion

Determination of maternal serum inhibin A in women with threatened abortion may be helpful in predicting the failure of pregnancies.

The TGF-beta superfamily and its roles in the human ovary and placenta

The transforming growth factor-beta (TGF-beta) superfamily consists of a large group of growth and differentiation factors, such as TGF-betas, activins, inhibins, growth and differentiation factors (GDFs), and bone morphogenetic proteins (BMPs). These molecules act through specific receptor complexes that are composed of type I and type II serine/threonine receptor kinases. The receptor kinases subsequently activate Smad proteins, which then propagate the signals into the nucleus to regulate target gene expression. Several ligands in this family, such as TGF-betas, activins, inhibins, BMP-15, and GDF-9, play important roles in regulating human ovarian functions, including follicle development and maturation. Activin and TGF-beta are also involved in regulating placental development and functions. Abnormal expression or function of these ligands has been found in several pathological conditions. This review summarizes the role of the TGF-beta superfamily in human ovarian and placental regulation and function, and the potential clinical implications.

Use of serum inhibin A and human chorionic gonadotropin measurements to predict the outcome of in vitro fertilization pregnancies

OBJECTIVE

To assess the clinical value of maternal serum inhibin A measurements in early pregnancy in the prediction of outcome of IVF pregnancies and to compare the predictive accuracy of inhibin A concentrations with serum hCG concentrations.

DESIGN

Retrospective study.University-based IVF program.

PATIENT(S)

One hundred fifty IVF pregnancies of 150 couples were studied during a 4-year period.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The association between pregnancy outcome and age, number of collected oocytes, number of transferred embryos, and serum hCG and inhibin A concentrations in early pregnancy was studied with logistic regression. Predictive accuracy of inhibin A and hCG concentrations was calculated by receiver-operating characteristic (ROC) analysis.

RESULT(S)

Lower serum concentrations of inhibin A and hCG were associated with increased odds for preclinical abortion and early pregnancy loss, whereas higher inhibin A and hCG concentrations were observed in multiple ongoing pregnancies. Inhibin A measurements were superior to hCG in the prediction of preclinical abortions; no significant difference was observed between the predictive value of hCG, inhibin A, or their combination in differentiating between ongoing pregnancies and early pregnancy losses. The discriminative potential of inhibin A for prognosticating multiple ongoing pregnancies was lower than that of hCG.

CONCLUSION(S)

Although serum inhibin A concentrations are more accurate than hCG levels for predicting preclinical abortion after IVF, they had no advantage in forecasting ongoing or multiple ongoing pregnancies, suggesting that routine assessment of serum inhibin A concentrations during follow-up of IVF pregnancies is unjustified.