Adrenomedullin and nitric oxide synthase at the maternal-decidual interface in early spontaneous abortion.

OBJECTIVE

To investigate local and systemic nitric oxide (NO) and adrenomedullin (AM) production in spontaneous abortion.

STUDY

DESIGN

Plasma samples and placental specimens were collected from 25 women with spontaneous abortion (6-12 weeks of gestation) and 25 women who underwent voluntary pregnancy termination. NO and AM levels were assayed in plasma; placental NO isoenzymes (inducible NOS and endothelial NOS) and AM distribution and localization were determined by immunohistochemistry.

RESULTS

Plasma NO and AM concentrations were similar in spontaneous abortion and controls. In the placenta both iNOS and AM were localized at the fetomaternal interface, and the prevalence of positive cells, particularly of trophoblast cells, stained for iNOS and AM was significantly lower in spontaneous abortions than in controls.

CONCLUSION

The presence of iNOS and AM at the maternal-placental interface in early pregnancy suggests a potential role of NO and AM in implantation and early gestational development. Differences in immunostaining intensity and prevalence for both iNOS and AM in spontaneous abortion may reflect functional modifications of placental bed tissue.