Beneficial effects of GnRH agonist administration prior to ovarian stimulation for patients with a short follicular phase.

ABSTRACT

A short follicular phase is an early clinical feature of declining reproductive competence. The shortening of the follicular phase length is related to both advanced recruitment and selection of the dominant follicle secondary to an earlier and higher FSH rise during the luteal-follicular transition, while the late follicular growth is normal. As a short follicular phase may be detrimental for reproduction, it was postulated that increasing the duration of follicular phase could improve conception rate. For that purpose, gonadotrophin-releasing hormone agonist minidoses were administered in the mid-luteal phase to prevent the intercycle FSH rise before tailoring follicular growth by controlled exogenous FSH administration. This regimen, applied to 69 infertile ovulatory women with a short follicular phase (9.6 +/- 1.2 days) actually lengthened the follicular phase by about 3 days. It proved to be effective in 179 cycles to induce paucifollicular development (1.8 +/- 0.9 follicles) with a low cancellation rate (4%) and a moderate requirement for gonadotrophins [13.3 +/- 6.3 ampoules (75 IU)]. In those women with a high frequency (80%) of elevated basal FSH or oestradiol concentrations, the pregnancy rate reached 15.1%/cycle but the miscarriage rate remained high (44%). Thus, increasing the follicular phase length in patients with a short follicular phase may partially restore fecundity.