ACCUMULATION OF HUMAN CHORIONIC-GONADOTROPIN IN THE SERUM OF PATIENTS DURING IN-VITRO FERTILIZATION TREATMENT CYCLES WITH PERGONAL

We examined the possible contribution of human chorionic gonadotrophin (HCG) in Pergonal to the serum luteinizing hormone (LH)-like bioactivity in 10 patients (median age 32 years, range 28-38) with tubal infertility who were undergoing in-vitro fertilization (IVF), together with 19 controls (median age 30 years, range 21-43). IVF patients were treated with clomiphene (50 mg twice daily) over days 2-6 and Pergonal (150 IU i.m.) daily from day 5 until at least day 10. Serum LH was measured by fluoro-immunometric assay (I-LH) and in-vitro Leydig cell bioassay (B-LH). Serum HCG was measured by fluoro-immunometric assay. The data were analysed by paired two-tailed t-test, following logarithmic transformation. From days 1-5, there was an increase in serum B-LH (mean, 95% confidence intervals given in parentheses) from 8.3 (6.8, 10.2) IU/l to 11.7 (9.8, 13.9) IU/l [P = 0.004], and in serum I-LH from 4.5 (3.7, 5.4) IU/l to 5.4 (4.6, 6.3) IU/l [P = 0.002]. From days 5-8, there was a rise in B-LH to 16.6 (12.6, 21.9) IU/l [P = 0.023]. The rise in I-LH to 6.3 (5.1, 7.8) IU/l [P = 0.081] failed to reach significance. Furthermore, serum HCG was <0.75 IU/l until after Pergonal was administered on day 5, then rose to a plateau on day 8 at 1.2 (0.8, 1.6) IU/l. Serum HCG in the controls remained <0.75 IU/l throughout. We conclude there is a disproportionate increase in serum B-LH compared to I-LH from days 5-8, corresponding with a rise in serum HCG and the commencement of treatment with Pergonal. The HCG in Pergonal may be contributing to an undesirable rise in serum LH-like bioactivity, which might reduce the success rate of IVF.