Dados do Trabalho

Title

Association of thrombophilic and immunological factors with recurrent pregnancy loss.

Objective

Recurrent pregnancy loss (RPL) is defined as the loss of two or more consecutive pregnancies. The possible causes of RPL can be genetic, thrombophilic, immunological, among others, however, in approximately 30% the cause is unknown. Therefore, the objective of this study was to evaluate the association of thrombophilic (acquired and hereditary) and immunological (autoimmune and alloimmune) factors with recurrent pregnancy loss.

Methods

Case-control study, paired 1 control to 4 cases. It included 53 women with recurrent pregnancy loss in whom genetic analysis was performed on the abortion material, being the Aneuploid Group (control, n= 10) and the Euploid Group (study, n= 43). Study approved by the Ethics and Research Committee under protocol CAAE 79524317.1.0000.0018.
Exclusion criteria: presence of known factors for RPL. A panel of acquired thrombophilia (IgG and IgM anticardiolipin, lupus anticoagulant), hereditary (protein C and S, prothrombin mutation, factor V Leiden, MTHFR 677 and 1298, antithrombin III, homocysteine), autoimmune immunological (ANA, anti DNA, antithyroglobulin, TSH, TRAB) and alloimmune (NK cell activity, CH50 and C3).
Categorical variables compared with Chi-square or Fisher, continuous with t-test and associations with logistic regression, significant differences when p<0.05.

Results

We found no differences between the Aneuploid Group versus the Euploid Group in age (35.6 vs. 36.0 years, P=0.753), antral follicle count (13.4 vs. 15.3, P=0.646) and FSH on day 3 of the menstrual cycle (7.1 vs. 5.9, P=0.317).
Comparing the autoimmune factors (aneuploid versus euploid group), we found an association: ANA (25.0% vs 12.0%), TSH and antithyroglobulin (40.0% vs 25.8%, P=0.603). Likewise in the comparison of alloimmune factors: NK cell activity, CH50 and C3.
As for thrombophilic factors, we found no association in any evaluated parameter, whether acquired (IgG and IgM anticardiolipin, lupus anticoagulant), or hereditary (Protein C, Protein S, Prothrombin mutation, Factor V Leiden, MTHFR 677 and 1298, Antithrombin III, Homocysteine).

Conclusion

We compared whether recurrent pregnancy loss patients with embryonic euploidy could have present thrombophilic or immunological factors that could be associated with loss when compared with the group with RPL due to aneuploidy. We found no association of any factor, suggesting that patients with RPL even with an euploid embryo must have other causes, not those evaluated in this study.

Keywords

Aneuploidy; Immunological factors; Thrombophilias; recurrent pregnancy loss