Purpose: Vaginal progesterone administration starting on the day of oocyte retrieval induced a decrease in uterine contraction frequency on the day of embryo transfer (ET) as compared with preovulatory values. Uterine relaxation before ET is likely to improve outcome by avoiding displacement of the embryo from the uterine cavity (Fanchin, Righini, de Ziegler, Oliviennes, Ledée, Frydman: Fertil Steril 2001;75:1136-1140). The objective of the present study was to determine whether the early use of vaginal progesterone on the day of oocyte retrieval may alter the embryo implantation and pregnancy rates.
Methods: A total of 103 patients were submitted for ovarian stimulation with GnRH-a and recombinant FSH (Puregon, Organon) for the application of invasive assisted reproduction techniques (ICSI). The patients were divided into two groups in a prospective and randomized manner: Group A (n = 51) where application of vaginal progesterone started (Utrogestan, Besins International) at the dose of 400 mg from the evening of the day of oocyte retrieval, and Group B (n = 52) started to apply vaginal progesterone at the same dose but from the evening of embryo transfer (2nd day).
Results: The age of Group A patients (34.2 +/- 4.6) was similar (p = 0.50) to that of Group B patients (34.8 +/- 4.9). The number of oocytes retrieved and at metaphase II from Group A patients (10.6 +/- 6.9 and 7.8 +/- 6.0; respectively) did not differ significantly (p = 0.84 and p = 0.49, respectively) from the number of oocytes retrieved and metaphase II from Group B patients (10 +/- 5.6 and 6.7 +/- 4.7, respectively). Also, there was no difference (p = 0.48) in number of embryos transferred to Group A patients (2.7 +/- 0.8) versus Group B patients (2.7 +/- 0.9). Embryo implantation and pregnancy rates for Group A patients (12.6 and 27.4%, respectively) were equal (p = 0.98 and p = 1.0, respectively) to those for Group B patients (13.4 and 28.8%, respectively).
Conclusion: Vaginal progesterone at the dose of 400 mg started on the day of oocyte retrieval did not increase implantation or pregnancy rates when compared to the same dose started on the day of embryo transfer.