Gonadotropin-releasing hormone agonist administration in early human pregnancy is associated with normal outcomes

Quantitative Gonadotropin-Releasing Hormone Gene Expression and Immunohistochemical Localization in Human Endometrium Throughout the Menstrual Cycle1

“…Encouraged by the evidence that large doses of GnRH or GnRH-a were able to induce abortion or delay implantation in rats and baboon monkeys [7,59], one of the first clinical GnRH-a experiments in humans was to assess a possible postcoital and postimplantation contraceptive effect. The surprising outcomes of those studies was that high doses of super-reactive GnRH-a not only failed to block implantation or induce abortion in humans [60] but rather seemed to enhance implantation [24][25][26][27][28][29][30][31][32][33][34][35][36]. The exact mechanism by which GnRH-a favors pregnancy during the periimplantation period has remained unknown until present.…”

“…The inadvertent exposure of human pregnancy during the early stages of embryonic implantation to GnRH-a has been reported in IVF patients, and the clinical experience in those cases has suggested not only that undesired effects are unlikely but that the analogue might enhance implantation [24][25][26][27][28][29][30][31][32][33][34][35][36]. Moreover, it has been reported that patients with long history of infertility and unsuccessful treatment by different modalities have conceived repeatedly under the administration of GnRH-a [26,37], with the suggestion that these conceptions may have been favored by the analogue.…”

GnRH in pregnancy

“…It is not known how GnRH and analogues exert their antipregnancy effects, but it is well accepted that the mechanism is through its antiprogesterone action, involving direct or indirect influence on progesterone production and secretion. However, 18 pregnancies in women who were treated with GnRH analogue for a period of 10 to 24 days during unrecognized early pregnancy, had a normal outcome [33].…”

GnRH agonist for luteal support in IVF? Setting the balance between enthusiasm and caution

“…The assurance that today's safe use is warranted is partly based on the notion that administration takes place before embryo transfer thus minimizing the chance of embryonic exposure. In addition, the relative assurance that human embryonic exposure will not be harmful is based on series of individual case reports about accidental administration to pregnant women (Golan et al, 1990;Isherwood et al, 1990;Ron-El et al, 1990;Smitz et al, 1991;Jackson et al, 1992;Balasch et al, 1993;Elefant et al, 1993;Har-Toov et al, 1993;Weissman and Shoham, 1993;Wilshire et al, 1993;Young et al, 1993;Gartner et al, 1997).…”

“…The first was the report by Tesarik et al (2004). They envisaged luteal administration as a voluntary therapeutic action to enhance implantation based on the impression that the inadvertent GnRH agonist administered in the luteal phase supported rather than compromised implantation (Golan et al, 1990;Isherwood et al, 1990;Ron-El et al, 1990;Smitz et al, 1991;Jackson et al, 1992;Balasch et al, 1993;Elefant et al, 1993;Har-Toov et al, 1993;Weissman and Shoham, 1993;Wilshire et al, 1993;Young et al, 1993;Gartner et al, 1997). In a prospective randomized manner in an oocyte donor programme, two recipients received either a single injection of GnRH agonist (triptorelin) 6 days after ICSI or a placebo sharing the oocytes from a single donor (Tesarik et al, 2004).…”