Endogenous luteinizing hormone surge during superovulation induction with sequential use of clomiphene citrate and pulsatile human menopausal gonadotropin.

There is dispute as to whether an endogenous LH surge occurs in women during follicle stimulation with human menopausal gonadotropin (hMG) for in vitro fertilization (IVF). In this study, 12 consecutive normally cycling women with tubal infertility were treated with clomiphene citrate and hMG for ovulation induction and subsequent IVF. Beginning on the fifth day of clomiphene administration (150 mg daily for 5 days), 225 IU hMG were given daily sc in a pulsatile manner (28 IU/3 h). All women had an endogenous LH surge which started on the seventh to ninth day of hMG administration. The mean duration [25.5 +/- 1.0 (+/- sem) h] and the mean peak value (38.9 +/- 4.7 U/liter) of the LH surge were less than those in spontaneous cycles. However, luteinization of at least some of the follicles occurred, based on findings of supraphysiological levels of serum progesterone during the surge and subsequent increase in urinary pregnanediol levels (luteal phase). Preovulatory oocytes were recovered via laparoscopy 34-35 h after the onset of the surge, and these oocytes cleaved after IVF. One pregnancy was achieved after embryo transfer, which resulted in abortion. These results represent the first demonstration that an attenuated LH surge is obtained in normally cycling women during superovulation induction with sequential clomiphene/pulsatile hMG treatment.