Accumulation of human chorionic gonadotrophin 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)-likebioactivity in 10 patients (median age32 years, range 28–38)with tubal infertility who were undergoing in-vitro fertilization(IVF), together with 19 controls (median age30 years, range21–43). IVF patients were treated with clomiphene (50mg twice daily) over days 2–6 and Pergonal (150 IU i.m.)daily from day 5 until at least day 10. Serum LH was measuredby fluoro-immunometric assay (I-LH) and in-vitro Leydig cellbioassay (B-LH). Serum HCG was measured by fluoro-immunometricassay. The data were analysed by paired two-tailed t-test, followinglogarithmic transformation. From days 1–5, there was anincrease in serum B-LH (mean, 95% confidence intervals givenin parentheses) from 8.3 (6.8, 10.2) IU/1 to 11.7 (9.8, 13.9)IU/1 P= 0.004], and in serum I-LH from 4.5 (3.7, 5.4) IU/1to 5.4 (4.6, 6.3) IU/1 P= 0.002]. From days 5–8, therewas a rise in B-LH to 16.6 (12.6, 21.9) IU/1 P= 0.023]. Therise in I-LH to 6.3 (5.1, 7.8) IU/1 P= 0.081] failed to reachsignificance. Furthermore, serum HCG was <<0.75 IU/1 untilafter Pergonal was administered on day 5, then rose to a plateauon day 8 at 1.2(0.8, 1.6) IU/1. Serum HCG in the controls remained<<0.75 IU/1 throughout. We conclude there is a disproportionateincrease in serum B-LH compared to I-LH from days 5–8,corresponding with a rise in serum HCG and the commencementof treatment with Pergonal. The HCG in Pergonal may be contributingto an undesirable rise in serum LH-like bioactivity, which mightreduce the success rate of IVF.