Comparison of luteal phase profile in gonadotrophin stimulated cycles withor without a gonadotrophin-releasing hormone antagonist

The aim of our study was to explore luteal phase hormone profiles in gonado trophin-stimulated cycles with or without gonadotrophin-releasing hormone ( GnRH) antagonist therapy during intrauterine insemination (IUI). Forty-one infertile couples were recruited in this randomized clinical study. METHODS : The 19 patients included in group A were treated for 21 cycles with recom binant FSH 150 IU/day starting from day 3 of the cycle and with the GnRH an tagonist cetrorelix at the dose of 0.25 mg/day starting from the day in whi ch a follicle with a mean diameter of greater than or equal to 14 mm was se en at ultrasound scan. Cetrorelix was administered until human chorionic go nadotrophin (HCG) administration. The 22 patients included in group B were administered recombinant FSH alone at the same dosage for 27 cycles. RESULT S: The two treatment groups showed a similar increase in progesterone conce ntration during the luteal phase. In the mid-luteal phase (day 6 after HCG) , oestradiol concentrations in group B were significantly higher compared w ith group A (P < 0.05) but the oestradiol:progesterone ratio was similar in the two groups. Serum LH was completely suppressed during the follicular p hase only in group A, concomitantly with GnRH antagonist administration. A total of six pregnancies, all ongoing, were achieved (14.3% per patient and 12.2% per cycle), equally distributed in group A and in group B. CONCLUSIO N: GnRH antagonists can be safely administered in gonadotrophin-stimulated IUI cycles without luteal phase supplementation because no deleterious effe cts of GnRH antagonist administration were noted on luteal progesterone con centration or on the duration of the luteal phase.