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

Spontaneous pregnancies associated with inadvertent periconceptional administration of a gonadotrophin-releasing hormone agonist (GnRHa) occur in approximately 1% of in-vitro fertilization (IVF) cycles. The two main issues to be considered in these circumstances are the luteolytic effect of the agonist and embryotoxicity. In addition, some authors have suggested a higher incidence of ectopic implantations. In view of these concerns, we report on 15 patients who conceived during pituitary desensitization with a GnRHa in the luteal phase of the menstrual cycle, and review the literature on the subject. A detailed analysis of the data available so far, which include 59 pregnancies exposed to GnRHa, shows that: (i) there is no clinical evidence for impaired luteal function, and hormonal supplementation does not improve pregnancy outcome; (ii) with only two cases of reported minor malformations among 37 deliveries, both having a genetic component, there is no evidence of teratogenic effects; and (iii) ectopic implantations in these circumstances are related to tubal disease but not to the drug. Considering the long history of infertility in these patients who had previously been treated unsuccessfully by different therapeutic modalities, it is likely that the occurrence of those pregnancies is not merely coincidental and that GnRHa might have a positive role in fecundity. The improved fecundity may be explained by the mechanisms of luteinizing hormone action in the corpus luteum.