Inadvertent gonadotrophin-releasing hormone agonist (GnRHa) administration in the luteal phase may improve fecundity in in-vitro fertilization patients

Spontaneous pregnancies associated with inadvertent periconceptionaladministration of a gonadotrophin-releasing hormone agonist(GnRHa) oocur in 1% of in-vitro fertilization (IVF) cycles.The two main issues to be considered in these circumstancesare the luteolytic effect of the agonist and embyrotoxicity.In addition, some authors have suggested a higher incidenceof ectopic implantations. In view of these concerns, we reporton 15 patients who conceived during pituitary desensitizationwith a GnRHa in the luteal phase of the menstrual cycle, andreview the literature on the subject. A detailed analysis ofthe data available so far, which include 59 pregnancies exposedto GnRHa, shows that: (i) there is no clinical evidence forimpaired luteal function, and hormonal supplementation doesnot improve pregnancy outcome; (ii) with only two cases of reportedminor malformations among 37 deliveries, both having a geneticcomponent, there is no evidence of teratogenic effects; and(iii) ectopic implantations in these circumstances are relatedto tubal disease but not to the drug. Considering the long historyof infertility in these patients who had previously been treatedunsuccessfully by different therapeutic modalities, it is likelythat the occurrence of those pregnancies is not merely coincidentaland that GnRHa might have a positive role in fecundity. Theimproved fecundity may be explained by the mechanisms of luteinizinghormone action in the corpus luteum.