LH suppression following different low doses of the GnRH antagonist ganirelix in polycystic ovary syndrome

Overnight luteinizing and follicle stimulating hormone profiles during GnRHa treatment in short girls born small for gestational age

BACKGROUND

Since puberty starting at a height less than 140 cm might reduce adult height, postponement of puberty was studied in short pubertal girls born SGA. Data on overnight LH and FSH profiles during GnRHa treatment are very limited.

AIMS

To evaluate whether 3 months of GnRHa treatment results in sufficient suppression of pubertal LH and FSH profile patterns. To evaluate whether girls show sufficient pubertal suppression according to a consensus-based peak LH cut-off level of 3 IU/l during a GnRH agonist test.

PARTICIPANTS

Twenty-one short pubertal girls born SGA.

INTERVENTION

After baseline LH and FSH profiles, children received leuprorelide acetate depots of 3.75 mg subcutaneously, every 4 weeks.

RESULTS

At baseline, amplitude and frequency of LH and FSH pulsatility were higher in girls with breast stage 3, compared to girls with breast stage 2. After 3 months of GnRHa treatment, all girls showed clinical arrest of puberty and their LH and FSH levels during overnight profiles had significantly decreased to prepubertal levels. In contrast, peak LH during the GnRH agonist test indicated insufficient pubertal suppression in 33% of girls. No differences in LH and FSH profiles were found between girls with a peak LH above or below 3 IU/l.

CONCLUSION

After 3 months of GnRHa treatment, central puberty was adequately suppressed in all girls, as shown by the prepubertal LH and FSH profiles. The GnRH agonist falsely indicated insufficient pubertal suppression in 33% of these girls.

GnRH pulsatility, the pituitary response and reproductive dysfunction

GnRH plays an essential role in neuroendocrine control of reproductive function. In mammals, the pattern of gonadotropin secretion includes both pulse and surge phases, which are regulated independently. The pulsatile release of GnRH and LH plays an important role in the development of sexual function and in the normal regulation of the menstrual cycle. The importance of GnRH pulsatility was established in a series of classic studies. Fertility is impaired when GnRH pulsatility is inhibited by chronic malnutrition, excessive caloric expenditure, or aging. A number of reproductive disorders in women with including hypogonadotropic hypogonadism, hypothlamic amenorrhea, hyperprolactinemia and polycystic ovary syndrome (PCOS) are also associated with disruption of the normal pulsatile GnRH secretion. Despite these findings, the molecular mechanisms of this pulsatile GnRH regulation are not well understood. Here, we review recent studies about GnRH pulsatility, signaling and transcriptional response, and its implications for disease.

Gonadotropin-releasing hormone antagonist in in vitro fertilization superovulation

The use of gonadotropin-releasing hormone (GnRH) antagonists in in vitro fertilization superovulation remains controversial. The GnRH agonist 'long protocol' has been seen as the gold standard for many years. Comparisons and meta-analyses of the efficacy of GnRH antagonists and agonists have been largely inconclusive, with the dataset being contaminated with outdated reports of poorer efficacy with GnRH antagonists, which have stemmed from studies of their use as a second-line drug in older women and women who were poor responders. This work cannot reflect the actual clinical effectiveness of GnRH antagonist and must be interpreted with care. The major advantages of GnRH antagonists use in superovulation include a gentler and more patient-friendly stimulation cycle with less hypoestrogenic side effects, with the potential to lower the risk of ovarian hyperstimulation and enhanced embryo growth. Our current clinical experience with GnRH antagonists in in vitro fertilization is limited, although there are a growing number of in vitro fertilization centers embracing this new technology. There is a clear need for a modern, suitably powered clinical trial to demonstrate the place of GnRH antagonist-based superovulation protocols and in subgroups of patients, such as polycystic ovary syndrome or poor responders.