Low Periconceptional Maternal Serum Thymosin α1 Levels Are Associated With Blighted Pregnancies

OBJECTIVE: The thymus-derived peptides, thymosin α₁ and thymosin (β₄, are believed to contribute to the maintenance of immune homeostasis. They are also associated with the hypothalamic-pituitary-adrenal-gonadal axis and may play a role in reproduction. STUDY DESIGN: Patients were recruited from a university hospital setting. Eligible candidates were 24 to 38 years old who were being seen in an ovulation induction and in vitro fertilization program. Serial maternal serum thymosin α₁ and β₄ levels were assayed preconceptual and then twice in the first trimester by ELISA in 28 women with known ovulation dates who successfully conceived as demonstrated by positive serum β human chorionic gonadotropin (hCG). Thymosin α₁ and β₄ serum levels for viable pregnancies (group I; N = 19) were compared to pregnancies that aborted (group II; N = 9) using repeated measures of multivariate analysis of variance (MANOVA). Periconceptional (preovulatory and early pregnancy) thymosin α₁ and β₄ values between groups I and II were compared using repeated measure one-way ANOVA. RESULTS: Thymosin α₁ levels from pregnancies that remained viable were significantly higher than those from pregnancies that spontaneously aborted. Preovulation thymosin α₁ levels also tended to be lower in pregnancies that subsequently aborted. Thymosin β₄ levels were similar between the two groups. CONCLUSIONS: Decreased maternal serum thymosin α₁ levels may be associated with periconceptional endocrine and/or immune disturbances preceding miscarriage.