Role of periovulatory luteinizing hormone concentrations during assisted reproductive technology cycles stimulated exclusively with recombinant follicle-stimulating hormone

Objective: To study the effect of endogenous luteinizing hormone (LH) conce ntration on fertilization, pregnancy, and early pregnancy loss rates. Design: Retrospective cohort study. Setting: Tertiary-care university cente r. Patient(s): One hundred sixty-six normogonadotropic patients undergoing IVF . Intervention(s): Luteal phase pituitary down-regulation and recombinant FSH (Gonal-F) were used for ovarian stimulation. The mean of 4-5 serum LH conc entrations, from stimulation days 5-12, was computed for analysis. Main Outcome Measure(s): Fertilization, pregnancy, and early pregnancy loss rates according to periovulatory levels of LH. Result(s): Data were analyzed by stratifying patients according to a mean p eriovulatory LH value of 3 mIU/mL. After controlling for confounding variab les with logistic regression, results showed that the fertilization rate wa s significantly lower in patients with a periovulatory LH <3 mIU/mL versus <greater than or equal to>3 mIU/mL (52% and 58%, respectively; P=.03). Preg nancy rates and spontaneous abortion rates were similar in both groups. The re were seven biochemical pregnancies, all in patients with an LH <3 mIU/mL (P=.07). Conclusion(s): Low endogenous LH concentrations (<3 mIU/mL) in the late fol licular phase of an IVF cycle are associated with significantly lower ferti lization rates and a trend toward higher biochemical pregnancy rates. It ma y be of clinical benefit, when exclusively using r-hFSH in ART cycles, to a dd LH in the late follicular phase or to further reduce the dose of GnRH ag onist. (C) 2001 by American Society for Reproductive Medicine.