Transfer of frozen-thawed embryos in artificially prepared cycles with andwithout prior gonadotrophin-releasing hormone agonist suppression: a prospective randomized study

Transfer of frozen-thawed embryos is usually carried out in a natural cycle or in a programmed cycle in which the endometrium is exogenously stimulate d following downregulation of the hypophysis, To analyse the possibility th at the programmed cycle for embryo transfer can still be hormonally manipul ated without the use of gonadotrophin-releasing hormone agonist (GnRHa) we have conducted a prospective randomized study that compared the outcome of frozen-thawed embryo transfer cycles using micronized 17 beta-oestradiol an d micronized progesterone preparations with and without the concomitant use of GnRHa. One hundred and six patients were randomly divided into two grou ps, In group A (53 patients) 4 mg/day of micronized 17 beta-oestradiol was initiated following down-regulation of hypophysis, In group If (53 patients ) oestrogen stimulation started on day 1 of the cycle without prior pituita ry downregulation using a dose of 6 mg/day for 7 days. In both groups, micr onized progesterone in a dose of 900 mg/ day was administered vaginally aft er at least 12 days of oestrogen stimulation. Embryo transfer embryo transf er took place 48-72 h thereafter according to the cryopreserved embryonic s tage, Overall, none of the patients had any follicular development and only one cycle in group If had to be cancelled because of premature progesteron e secretion. The two groups did not differ in age (31 +/- 5.6 and 31 +/- 5. 0 years), number of embryos transferred per patient (3.4 +/- 1.2 and 3.3 +/ - 1.0), and day of progesterone initiation (15 +/- 2.2 and 15 +/- 1.9 fur g roups A and If respectively). The endometrial thickness on the day of proge sterone initiation was comparable in both groups (11 +/- 1.6 and 10 +/- 1.6 mm for groups A and If respectively). Similarly, the pregnancy rate per em bryo transfer and implantation rate in group A (26.4% and 9.5%) were compar able to those of group B (21.1% and 9%). These results indicate that progra mmed cycles can be successfully applied by administering a high dose of mic ronized 17 beta-oestradiol starting on day 1 of the cycle. Compared to GnRH a programmed cycles, this approach is simpler, more convenient fur both the patient and medical staff, and results in a similar success rate at a lowe r cost.