Objective: To examine the value of combined maternal serum inhibin A and embryonic/fetal heart rate to predict the pregnancy outcome in a first-trimester threatened abortion.
Materials and method: This was a prospective observational study. The authors measured maternal serum inhibin A and the embryonic/fetal heart rate in women with a clinical diagnosis of a threatened abortion and in normal pregnant women. The main outcome measured was ongoing normal pregnancies.
Results: Thirty women with threatened abortions and 30 normal pregnant women were followed. Three women with threatened abortions ended in failed pregnancies. The mean embryonic/fetal heart rate and the median of serum inhibin A in the threatened abortion group were not different from the control group. In women with threatened abortions and failing pregnancies, the embryonic/fetal heart rate (101.7 +/- 20.1 beats/min) was significantly lower than in women with threatened abortions but ongoing pregnancies (163.3 +/- 19.7 beats/min, p = 0.024). Serum inhibin A in women with threatened abortions and failing pregnancies was not different from women with threatened abortions but ongoing pregnancies (median) 274.0 vs. 559.9 pg/mL, p = 0.388). When using serum inhibin A combined with embryonic/fetal heart rate, or only embryonic/fetal heart rate, the sensitivity and specificity for predicting an ongoing pregnancy were 100% and 50% or 100% and 100%, respectively.
Conclusion: Combined maternal serum inhibin A and embryonic/fetal heart rate is not better than embryonic/fetal heart rate for predicting the pregnancy outcome in a first-trimester threatened abortion.