To investigate the effects of recombinant (r-) LH supplementation in “low responder” patients undergoing ovarian stimulation with r-FSH for an IVF program. The apoptosis rate in cumulus cells was used as an indicator of oocyte quality.Comparison of the rate of DNA fragmentation and caspase-3 activity in cumulus cells in women stimulated with r-LH and r-FSH, versus patients treated with r-FSH alone (control).In vitro fertilization (IVF) laboratory.Forty patients undergoing assisted fertilization programs treated with a GnRH agonist, or r-FSH treatment begun on day 3 of the cycle (control). In the r-LH group, from day 8 of gonadotropin stimulation, 150 IU per day of r-LH were administered.Terminal deoxynucleotidyl transferase-mediated digoxigenin-deoxyuridine-triphosphate (dUTP) nick-end labeling (TUNEL) assay, and anti-caspase-3 cleaved immunoassay, to detect apoptosis in human cumulus cells.Difference in DNA fragmentation rate between cumulus cells derived from r-LH treatment and cumulus cells derived from control patients.No differences were observed between the two groups in the total amount of r-FSH administered and in the number of retrieved oocytes per patient. A statistically significant increase in the number of immature oocytes and in the E 2 serum peak was observed in the control group. The number of transferred embryos was significantly higher in the r-LH group. Pregnancy and implantation rates were higher in the r-LH group, but without statistical significance. The apoptosis rate in cumulus cells was higher in the control group than in the r-LH group.This study suggests that supplementation with r-LH improves the chromatin quality of cumulus cells involved in the control of oocyte maturation.