We sought to evaluate the influence of subtle serum progesterone elevation on in vitro fertilization (IVF) cycle outcome and to assess the impact of the type of gonadotropin-releasing hormone (GnRH)-analogue used during controlled ovarian hyperstimulation (COH) on the probability of clinical pregnancy.
We reviewed the files of all consecutive patients undergoing COH with either GnRH-agonist or antagonist in our IVF unit during a 10-year period and who had their peak serum progesterone levels determined on the day of human chorionic gonadotropin (hCG) administration.
Of the 2244 IVF cycles evaluated, 2103 had peak progesterone level of <1.5 ng/mL (normal-P group) and 141 of >1.5 ng/mL (high-P group) (6.28% of all the study population). Clinical pregnancy rate was significantly higher in the normal-P group (25.4% versus 16.6%; p < 0.006). Moreover, among the high-P group patients, the use of the long GnRH-agonist suppressive protocol (GnRH-ag) was more prevalent in patients who conceived as compared to those who did not (60.9% versus 39%, respectively; p < 0.05), with a tendency toward an increase pregnancy rate in those using GnRH-ag compared with GnRH-antagonist protocol (GnRH-antag; p < 0.059) COH protocols.
While subtle progesterone elevation in patients undergoing COH using GnRH-antag COH protocols, should dictate embryo cryopreservation and cancelation of the fresh transfer, in those undergoing the GnRH-ag COH protocol, a fresh embryo transfer should be recommended.