ESTRADIOL PRIMING IN IN VITRO FERTILIZATION

To determine the effect of follicular phase estrogen priming in IVF cycles. This retrospective cohort study was conducted in a university based IVF clinic between 2017-2021. Five hundred and fifty-one cycles were analyzed where study (116) and control (435) groups treated with GnRH antagonist fixed protocol while study group received additional 6mg/day of estrogen starting from the 1 st day of cycle until the hCG trigger and clomiphene citrate for 5-15 days. Only one cycle of each patient were included to the study so number of patients and cycles were equal. Primary outcomes were clinical pregnancy rate, live birth rate and gonadotropin consumption. Secondary outcomes were abortion rate, chemical pregnancy rate, ectopic pregnancy rate, multiple pregnancy rate and intrapartum exitus rate. Mean BMI was significantly higher in study group whilst all the remaining demographic properties were similar. Basal serum FSH levels (8.54 - 10.01, p=0.03), AFC (8.54 - 10.01, p=0.03), total gonadotropin consumption (1611.76 -2975.81, p=0.00) and ovarian stimulation duration (7.40 - 9.4, p=0.00) were significantly lower in study group while maximum serum LH level (10.12 -3.42, p = 0.00) and Pg level (1.52 - 1.00, p = 0.015) were statistically higher. Number of collected oocytes, M 1 and M 2 oocytes were similar for both groups where M 2 oocyte rate (71.3% - 75.0%, p = 0.04) was significantly higher in the control group. Post IVF results (number of ICSI, PN, cleavage, blast, transferred embryo, frozen embryo, fertilization rate, FORT and FOI) were similar for both groups. Single/twin pregnancy, single/twin birth, chemical pregnancy, ectopic pregnancy, abortion and intrapartum exitus rates were similar. Clinical pregnancy (29.4 -23.4, p< 0.01), single pregnancy (21.8-16.4, p< 0.01), total live birth (20.2 -14.8, p< 0.01) and single live birth (17.6 - 12.5, p< 0.01) rates represented an increasing trend in the study group with a p value < 0.01. This research supports the possibility of follicular phase estrogen priming in IVF cycles to increase the clinical pregnancy rates compared to conventional OS protocols while decreasing the gonadotropin consumption as it decreases financial burden of IVF cycles on patients and healthcare system.