Impact of Plasmatic Progesterone on the Day of Frozen Embryo Transfer in Hormone-induced Cycles.

Objective:  To establish a relationship between serum progesterone values on the day of frozen blastocyst transfer in hormone-replaced cycles with the probability of pregnancy, miscarriage or delivery.

Methods:  This was an ambispective observational study including all frozen-thawed embryo transfer cycles performed at our department following in vitro fecundation from May 2018 to June 2019. The outcomes evaluated were β human chorionic gonadotropin (β-hCG)-positive pregnancy and delivery. Groups were compared according to the level of serum progesterone on the day of embryo transfer: the 1 quartile of progesterone was compared against the other quartiles and then the 2 and 3 quartiles against the 4 quartile.

Results:  A total of 140 transfers were included in the analysis: 87 with β-HCG > 10 IU/L (62%), of which 50 (36%) delivered and 37 had a miscarriage (42%). Women with lower progesterone levels (< 10.7ng/mL) had a trend toward higher β-HCG-positive (72 versus 59%;  > 0.05), lower delivery (26 versus 39%;  > 0.05) and higher miscarriage rates (64 versus 33%;  < 0.01). Comparing the middle quartiles (P25-50) with those above percentiles 75, the rate of pregnancy was similar (60 versus 57%;  > 0.05), although there was a trend toward a higher number of deliveries (43 versus 31%;  > 0.05) and a lower number of miscarriages (28 versus 45%;  > 0.05). These differences were not statistically significant.

Conclusion:  There were no differences in pregnancy and delivery rates related with the progesterone level when measured in the transfer day. The miscarriage rate was higher in the 1 quartile group.