Dynamics of immunoreactive endothelin plasma levels during ovarian stimulation for in vitro fertilization with and without dietary sodium restriction

Objective: To investigate the correlation between immunoreactive endothelin plasma levels and both the number and size of follicles and its relationship with the development of ovarian hyperstimulation syndrome, in in vitro fertilization cycles, with and without dietary sodium restriction. Study design: Randomized study in an assisted reproduction unit of a large teaching hospital. Data of 88 women form the basis of this report (45 ad libitum sodium intake and 43 dietary sodium restriction). Non-parametric tests were used for statistical analysis. Results: Immunoreactive endothelin plasma levels neither correlate with the number of follicles, independent of their size, nor with the grade of ovarian hyperstimulation syndrome. Immunoreactive endothelin plasma levels decrease significantly in the luteal phase. These results are the same in both sodium diet groups. Conclusions: Immunoreactive endothelin plasma levels do not correlate with the number and size of follicles and they are not related to the development of ovarian hyperstimulation syndrome. These findings are independent of sodium intake.