To examine the temporal relationship among inhibin A, beta-hCG, and pro-alphaC in early pregnancy and to determine whether the measurement of these hormones has any role in prediction of pregnancy outcome in patients with recurrent spontaneous miscarriage.Prospective descriptive study.A tertiary referral center for recurrent miscarriage.Thirty-six pregnant women with previous history of recurrent spontaneous pregnancy loss.Serial blood samples were collected prospectively at 6, 8, 10, and 12 weeks of gestation and were analyzed for inhibin A and inhibin pro-alphac using a two-site enzyme-linked immunosorbent assay as well as for beta-hCG using the microparticle enzyme immunoassay.Serum levels of inhibin A, inhibin pro-alphac, and beta-hCG.The patients were allocated to two groups according to the pregnancy outcome: group 1 consisted of patients whose pregnancy continued beyond 20 weeks (control group); and group 2 consisted of patients who spontaneously aborted (aborted group). There was a significant difference in inhibin A concentrations between the control and aborted groups at 8, 10, and 12 weeks' gestation. Significant differences in beta-hCG concentrations between the two groups is evident only at 10 weeks' gestation. There were no significant differences in inhibin pro-alphac concentrations between the two groups at any gestational age. Assessment of the trend in the control group over the study period showed a significant increase in inhibin A and beta-hCG but not inhibin pro-alphac levels.Low serum levels of inhibin A at early gestational age in pregnancies destined to miscarry suggest a role for this glycoprotein as a marker for early pregnancy viability. Its measurement at the time of the first pregnancy test might be able to predict pregnancy outcome.