Faculty Bibliography

PURPOSE: Our objective was to determine if a change in serum P4 from day of transfer (defined as day 19) to day 28 could predict live birth outcome in patients undergoing IVF. METHODS: This study was a retrospective analysis of fresh IVF cycles from 2010 to 2013 at a single center. Primary outcomes include raw and percent change in serum P4, live birth rate, missed abortion, and biochemical pregnancies. RESULTS: Our results showed an association between live birth rate and percent change in P4. Patients with a 10% or greater drop in serum P4 from day 19 to day 28 had a lower live birth rate, at 26 versus 63%. Interestingly, both groups had "normal" serum P4 levels on day 19, but patients with a 10% or greater drop had lower P4 levels than their counterparts. There was no association between percent P4 change and spontaneous abortion or biochemical pregnancy. CONCLUSIONS: This is the first study to show that percent drop in serum P4 from day of transfer to day 28 is associated with decreased rates of live birth and ongoing pregnancy in fresh IVF cycles, even despite "high or normal" P4 levels on day of transfer.

Aromatase (estrogen synthetase; EC 1.14.14.1) catalyzes the demethylation of androgens' carbon 19, producing phenolic 18-carbon estrogens. Aromatase is most widely known for its roles in reproduction and reproductive system diseases, and as a target for inhibitor therapy in estrogen-sensitive diseases including cancer, endometriosis, and leiomyoma (141, 143). However, all tissues contain estrogen receptor-expressing cells, the majority of genes have a complete or partial estrogen response element that regulates their expression (61), and there are plentiful nonreceptor effects of estrogens (79); therefore, the effect of aromatase through the provision of estrogen is almost universal in terms of health and disease. This review will provide a brief but comprehensive overview of the enzyme, its role in steroidogenesis, the problems that arise with its functional mutations and mishaps, the roles in human physiology of aromatase and its product estrogens, its current clinical roles, and the effects of aromatase inhibitors. While much of the story is that of the consequences of the formation of its product estrogens, we also will address alternative enzymatic roles of aromatase as a demethylase or nonenzymatic actions of this versatile molecule. Although this short review is meant to be thorough, it is by no means exhaustive; rather, it is meant to reflect the cutting-edge, exciting properties and possibilities of this ancient enzyme and its products.

BACKGROUND: Progesterone (P4) is essential for support of the endometrium and implantation of an embryo in the normal menstrual cycle. In programed frozen embryo transfer cycles using exogenous P4 is necessary, as the endogenous production of P4 requires a functioning corpus luteum that is not present in programed cycles. To date, there is continuing debate about ideal serum estradiol and P4 values in frozen embryo transfer cycles. METHODS: Patients underwent single euploid embryo frozen transfer cycles from 2010 to 2013 at a single large academic center. Patients using donor oocytes and patients with changes in progesterone dose during the cycles in question were excluded. All cycles were programed and intramuscular P4 was used exclusively. Only patients administering the same daily dose of P4 throughout the cycle were included (N = 213 patients). Main outcomes were ongoing pregnancy/live birth rates (OPR/LBR), clinical pregnancy rates (CPR), and spontaneous abortions/biochemical pregnancies. CPR was defined by the presence of a sac on 1st trimester ultrasound. Missed abortions were calculated per pregnancy with a sac. Receiver operator characteristic curves (ROC curves) and chi-squared tests were performed for statistical analysis. RESULTS: Two groups based on day 19 P4 levels were compared (group A, P4 < 20 ng/ml; group B, P4 > 20 ng/ml). OPR/LBRs were 65 vs. 49 %, group A vs. B, p value = 0.02, RR = 1.33 (1.1-1.7). Missed abortion and biochemical rates were higher in group B as opposed to group A, 27 vs. 12 %, p = 0.01, RR = 0.45(0.24-0.86). When P4 was stratified into five groups based on nanogram per milliliter of progesterone on day 19 (10-15, 15-20, 20-30, 30-40, and >40), there was a trend downward in OPR/LBR (70, 62, 52, 50, and 33 %, respectively). There was also an increase in missed abortion/biochemical rates (7, 15, 27, 32, and 20 %, respectively). Multiple logistic regression showed an increase in OPR/LBR when accounting for age, day 2 FSH, weight, number of embryos biopsied, and number of euploid embryos. CONCLUSION: P4 levels >20 ng/ml on the day of transfer (during frozen single euploid embryo transfer cycles) were associated with decreased OPR/LBR.