INTRODUCTION
Currently, a large part of pregnancies and newborns after in vitro fertilization (IVF) cycles are obtained by cryopreserved embryo transfer (ET). Embryos transferred in deferred cycles need a previous endometrial preparation so that implantation can occur. There are different endometrial preparation protocols: hormone replacement therapy, stimulated cycle or natural cycle. The objective is to analyze the impact of the determination of serum progesterone (P) pre-transfer in patients undergoing blastocyst transfer in hormone replacement therapy (HRT) cycles for endometrial preparation, as well as to assess whether its supplementation in certain cases has any impact on the results.
MATERIALS AND METHODS
Retrospective cohort study, with cycles of embryo cryotransfer after in vitro fertilization. HRT was performed with oral estradiol valerianate and natural progesterone vaginally. In the study group P levels were measured on day +4 of progesterone treatment. Patients with levels below 10.0ng/dl, we supplemented 25 mg daily of subcutaneous progesterone. In patients with P >10.0ng/dl, the initial treatment was maintained. The control group consisted of patients with HRT without progesterone determination.
RESULTS
Study group 89 patients. Progesterone with low levels were found in 31.1%, with a median value of 8.8 ng/ml (7.4-9.5). Levels considered normal had a median value of 13.3 ng/ml (11.5-16.3) for the rest of the group. Abortion rates were significantly lower in the study group (10.4% versus 32.5%; p=0.01), with no differences in evolved pregnancy (47.8% versus 42.2%; p=0.5) when compared to the control group.
CONCLUSIONS
The present study suggests that P determination the day before embryo transfer may identify a subgroup of patients who would benefit from additional progesterone support, with an impact on reducing miscarriage rates.
