[Analysis of coagulation parameters in patients undergoing controlled ovarian hyperstimulation for in vitro...

Hyperestrogenic conditions have been related to alterations in the coagulation parameters. The objective of this study was to identify changes in coagulation parameters in women undergoing in vitro fertilization and embryo transfer (IVF-ET).

A group of 15 patients was studied prospectively, immediately before and during the course of an IVF-ET cycle. Blood was drawn in the preovulatory period of the cycle preceeding IVF-ET for complete blood count, fibrinogen, prothrombin time (TP), thromboplastin partial actived time (ATTP), coagulation time and estradiol. A another blood sample for the same tests was collected during controlled ovarian hyperstimulation, on the hCG day. Both samples were compared by a paired t-test.

There was an increase in fibrinogen (340.9 pg/mL to 383.1 pg/mL, p = 0.01). On the other hand, hematocrit levels decreased (40.5% to 38.4 %, p = 0.0001). The other coagulation tests showed no difference. Estradiol levels increased (167 pg/mL to 1435 pg/ml, p=0.0001), as expected during such treatment.

The data suggest a tendency towards an increase in coagulability, as expected in hyperestrogenic situations. However, even considering the statistical significance of the results, they might have limited clinical impact, since they were within the normal range. This study suggests that, despite the marked increase in estradiol and changes in coagulation parameters, IVF-ET is a safe procedure in terms of thromboembolic risks.