Relationship between midcycle luteinizing hormone surge quality and oocyte fertilization

Objective: To determine whether alterations in preovulatory follicular fluid (FF) levels of LH, FSH, and steroids are associated with the probability of fertilization. Design: Retrospective analysis of prospective study results. Setting: Reproductive medicine clinic of a university teaching hospital. Patient(s): Infertile women, with unstimulated, apparently regular cycles in an IVF research program. Intervention(s): Measurement of preovulatory FF levels of LH, FSH, E-2, and P and serum LH levels by fluoroimmunometry. Main Outcome Measure: Oocyte fertilization. Result(s): There were 84 transferable embryos (rate of normal fertilization and cleavage, 67%), and 41 oocytes (33%) failed to fertilize. Analysis of the matched FF showed that the median concentration of FF LH was significantly higher for cleaving embryos than for unfertilized oocytes (14.6 vs. 10.4 IU/L). Serum LH concentrations were similarly higher in cycles with cleaving embryos. There were no statistically significant differences in FF concentrations of FSH, E-2, or P in the two groups. Conclusion: Reduced preovulatory FF LH levels are associated with impaired fertilization of oocytes in vitro, despite normal FF FSH and steroid levels. (Fertil Steril(R) 2000;73:75-7. (C) 1999 by American Society for Reproductive Medicine.)