Increased risk of early pregnancy loss by profound suppression of luteinizing hormone during ovarian stimulation in normogonadotrophic women undergoing assisted reproduction

The impact of suppressed concentrations of circulating luteinizing hormone (LH) during ovarian stimulation on the outcome of in-vitro fertilization or intracytoplasmic sperm injection treatment in 200 consecutive, normogonado trophic women (couples) was analysed retrospectively. A standard stimulatio n protocol with mid-luteal gonadotrophin-releasing hormone (GnRH) agonist d own-regulation and ovarian stimulation with recombinant follicle Stimulatin g hormone (FSH) was used in all cases. Blood was sampled from each woman on stimulation days 1 and 8 for analysis of oestradiol and LH in serum. A thr eshold value of serum LH of 0.5 IU/I on stimulation day 8 (S8) was chosen t o discriminate between women with low or 'normal' LH concentrations, Low co ncentrations of LH on S8 (<0.5 IU/I) were found in 49% (98/200) of the wome n. This group of women was comparable with the normal LH group with regard to pre-treatment clinical parameters, and to the parameters characterizing the stimulation protocol with the exception of serum oestradiol concentrati on, which on S8 was significantly lower than in the normal LH group (P < 0. 001). The proportion of positive pregnancy tests was similar in the two gro ups (30% versus 34% per started cycle), but the final clinical treatment ou tcome was significantly different, with a fivefold higher risk of early pre gnancy loss (45% versus 9%; P < 0.005) in the low LH group and consequently a significantly poorer chance of delivery than in the normal LH group. It is concluded that a substantial proportion of normogonadotrophic women trea ted with GnRH agonist down-regulation in combination with FSH, devoid of LH activity, experience LH suppression, which compromises the treatment outco me. Whether these women would benefit from supplementation with recombinant LH or human menopausal gonadotrophin during ovarian stimulation, remains t o be proven in the future by prospective randomized trials.