Problem: The therapeutic value of progestogens in threatened abortion is still under debate. In the presence of sufficient progesterone levels during pregnancy, lymphocytes synthesize a mediator [progesterone-induced blocking factor (PIBF)] that is anti-abortive in mice. The aim of this study was to evaluate the effect of dydrogesterone on pregnancy outcome of threatened aborters.
Method of Study: Twenty-seven threatened aborters were treated for 10 days with dydrogesterone (30–40 mg/day). Sixteen healthy pregnant controls received no treatment. Serum progesterone and estradiol concentrations as well as urine PIBF concentrations were measured by enzyme-linked immunosorbent assay (ELISA).
Results: Pregnancy outcomes in dydrogesterone-treated threatened aborters did not statistically differ from those in healthy controls. Serum progesterone concentrations in control patients, but not those in threatened aborters increased as pregnancy progressed. Following dydrogesterone treatment, initially low PIBF concentrations of threatened aborters significantly increased (P = 0.001) to reach the PIBF level found in healthy controls.
Conclusions: These data suggest that by inducing PIBF production, dydrogesterone might improve pregnancy success rates in threatened aborters.