The Use of Human Ovarian Responsiveness in a New Bioassay for Follicle-Stimulating Hormone

Abstract

In a program of ovulation induction, 88 patients received more than one course of treatment with the same batch of human pituitary gonadotropin (hPG); 81 of these patients responded reproducibly in their repeat cycles. Of these, 68 also received at least two different batches of hPG in a total of 225 satisfactory treatment cycles. A model was developed which allowed the calculation of the relative patient potencies from the data obtained and the results were compared with the FSH and LH contents of the batches estimated by radioimmunoassay and with FSH estimates by the Steelman-Pohley and P. S. Brown bioassays. The results of the human assay correlated well with FSH values obtained by radioimmunoassay, less well with the FSH values obtained by the P. S. Brown assay, poorly with the values obtained by the Steelman-Pohley assay and not at all with the LH values obtained by radioimmunoassay after correction for the FSH effect. One batch which did not show this correlation had an exceptionally short plasma half-time of its contained FSH. The basal urinary estrogen excretion in the 81 patients showed an inverse correlation with hPG requirement, but this was of no value in predicting dosage. It was concluded that women provide a very satisfactory bioassay for the FSH content of hPG, providing the FSH/LH ratio is less than 1.0, and that the FSH content of batches determined by radioimmunoassay is the best laboratory guide for predicting potency in the human. Nevertheless, titration of dosage in the patient is still the only reliable method for achieving correct patient responses to hPG.