Clinical evidence for an LH 'ceiling' effect induced by administration of recombinant human LH during the late follicular phase of stimulated cycles in World Health Organization type I and type II anovulation.
BACKGROUND
The objective of these studies was to test the hypothesis that over-dosing with recombinant human LH (rLH) during the late follicular phase would suppress the development of follicles.


METHODS
Two double-blind studies were conducted. In study A, WHO I anovulatory patients received treatment with rFSH and rLH. When at least one follicle reached a mean diameter of 10-13 mm, patients were randomized using a computer-generated randomization list (stratified by centre) to rFSH and rLH (225 IU/day) (n = 8) or rLH alone (n = 6) or rFSH alone (n = 6). In study B, WHO II anovulatory patients with a hyper-responsive FSH were randomized to rLH (225 IU/day) (n = 4) or rLH 450 IU/day (n = 8) or placebo (n = 5).


RESULTS
Study A: the mean number of follicles >/=11 mm was 4.2 +/- 0.3 in the rFSH group, 1.5 +/- 0.7 in the rLH group and 6.0 +/- 2.3 in the rFSH/rLH group (P = 0.07). 0/8 patients presented follicular growth arrest in the rFSH group, but 4/6 in the rLH group and 1/6 in the rFSH/rLH did. Study B: 5/12 patients presented follicular growth arrest in the rLH groups, but none in the placebo group. The mean number of follicles >/=11 mm was 4.6 +/- 1.8 for the placebo group, 2.5 +/- 1.9 for the rLH 225 IU group and 4.2 +/- 1.4 in the rLH 450 IU group (not significant).


CONCLUSIONS
Results of this pilot study suggest that rLH alone can trigger follicular growth arrest in a significant number of patients, suggesting the existence of an 'LH ceiling' during late follicular maturation.
Loumaye
Ernest
E
Serono International, Reproductive Health Clinical Development Unit, Geneva, Switzerland.
Engrand
Patrick
P
Shoham
Zeev
Z
Hillier
Stephen G
SG
Baird
David T
DT
D000328:Adult; D000858:Anovulation / Q000145:classification / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D005640:Follicle Stimulating Hormone / Q000627:therapeutic use; D005498:Follicular Phase; D006801:Humans; D007986:Luteinizing Hormone / Q000008:administration & dosage*; D006080:Ovarian Follicle / Q000187:drug effects / Q000503:physiopathology; D010062:Ovulation Induction; D010865:Pilot Projects; D011995:Recombination, Genetic; D014944:World Health Organization
D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone