Progesterone levels on the day of embryo transfer using a single pessary of 400mg of vaginal progesterone vs. 200mg x2 pessaries in hormonal replacement cycles.

Objective: Does the use of 400mg pessaries of micronized progesterone provide comparable results as pessaries of 200mg x2, in terms of progesterone levels in hormonal replacement cycles for embryo transfer?.

Methods: Retrospective cohort study based on 299 embryo transfer treatments under artificial endometrial preparation carried out at Instituto Bernabeu. 131 patients received 1 pessary of 400 mg b.i.d. (group A) and 168 received 2 pessaries of 200 mg b.i.d. (group B).

Results: Mean serum progesterone levels were similar between groups (A: 13.64±4.47ng/mL vs. B: 13.88±7.17ng/mL). There were no differences in suboptimal progesterone levels between groups (A: 11.5% vs. B: 16.8%). In terms of patients receiving additional progesterone supplementation, there were no differences between groups (A: 26% vs. B: 35.3%.). No differences between groups were observed in clinical outcomes: pregnancy rate (PR) (A: 55% vs. B: 54.8%), biochemical pregnancy loss rate (BPLR) (A: 13.4% vs. B: 17.6%), miscarriage rate (MR) (A: 17.9% vs. B: 19.8%) and ongoing pregnancy rate (OPR) (A: 36.5% vs. B: 34.1%).

Conclusions: One progesterone pessary of 400mg (Cyclogest®) twice daily appears to be non-inferior to the use of two-200mg pessaries twice daily in terms of progesterone levels in HRT cycles.