The influence of dietary sodium restriction on renal and ovarian renin and prorenin production during ovarian stimulation.

In a prospective study, the effect of dietary sodium restriction on plasma and follicular fluid renin and prorenin concentrations and on fertilization measures was investigated during ovarian stimulation. In all, 18 women undergoing ovarian stimulation for in-vitro fertilization and embryo transfer were randomly divided into groups with and without sodium restriction. Plasma renin and prorenin concentrations were higher in the low sodium than in the normal sodium group. Plasma renin concentrations showed a mid-luteal rise. Plasma prorenin concentrations increased 4-fold on the day of oocyte retrieval, followed by a gradual decline to basal values. The low sodium group had more follicles than the normal sodium group. Neither follicular fluid renin and prorenin concentrations, nor the total amount of follicular fluid renin and prorenin per ovary differed significantly between the two groups. Oocyte yield and fertilization rates were similar in both groups. These rates were correlated with neither renin nor prorenin concentrations in follicular fluid. We conclude that sodium restriction did not influence cyclic plasma variation of renin or prorenin or follicular fluid renin and prorenin concentrations. In addition, fertilization rates were not affected by sodium restriction.