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) concentration on fertilization, pregnancy, and early pregnancy loss rates. DESIGN: Retrospective cohort study. SETTING: Tertiary-care university center. 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 concentrations, 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 periovulatory LH value of 3 mIU/mL. After controlling for confounding variables with logistic regression, results showed that the fertilization rate was significantly lower in patients with a periovulatory LH <3 mIU/mL versus > or = 3 mIU/mL (52% and 58%, respectively; P=.03). Pregnancy rates and spontaneous abortion rates were similar in both groups. There 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 follicular phase of an IVF cycle are associated with significantly lower fertilization rates and a trend toward higher biochemical pregnancy rates. It may be of clinical benefit, when exclusively using r-hFSH in ART cycles, to add LH in the late follicular phase or to further reduce the dose of GnRH agonist.