P-646 The effect of profound LH suppression in GnRH antagonist cycles on IVF/ICSI outcomes-A retrospective study of 400 cycles

Abstract Study question Does low pretrigger LH in GnRH antagonist cycles affect the blastulation rates and cumulative live birth rates? Summary answer Low does not frozen embryo transfer cycles. What is known already • There conflicting evidence that stimulated with recombinant FSH, serum may effect negatively pregnancy outcomes fresh transfer.(Benmachiche et al 2019). Whether observed of on or endometrial receptivity clear. design, size, duration Retrospective observational single centre study a population 400 undergoing IVF/ICSI between December 2018- 2021. Controlled ovarian stimulation Antagonist protocol unselected > 21yrs old IVF/ICSI. Exclusion Criteria- Long Flare Oocyte cryopreservation cycle Donor oocyte Participants/materials, setting, methods done according to hospital’s standard operations practice flexible human menopausal gonadotropins recombinant/urinary follicle stimulating hormone. When 3 more follicles >/=17mm, triggered Agonist dual trigger. pick up scheduled at 35-36hrs following Serum measured baseline Clinical embryological are assessed i.e., <1.5MIU/ML normal >/= 1.5 MIU/ML. Main results role chance Demographic variables were comparable both arms, except subjects LH. Mean dose although statistically significant, slightly higher group. group significant. number oocytes retrieved, mature oocytes, fertilisation rate, blastocysts, day5 day6 blastocyts, good quality blastocysts similar Outcomes LH- blastocysts- 5.02 +/-3.84 vs 4.72 +/-3.82 (p = 0.44) 4 (0-14) 3.5(0-20) 0.86) 1 (0-8) (0-9) 0.4) 2(0-19) 2 (0-17) 0.68 ) Number no 11.1 16.1% 0.35) Cumulative rate 47 48% 0.99) SECONDARY OUTCOMES- gonadotropins- 3282+/- 913 iu 3119 926iu 0.07) stimulation- 11.67 +/- 1.87days 11.09 2days 0.01) retrieved-14.98+/- 7.14 13.9+/-7.9 0.15) oocytes-11.19+/- 5.64 10.43+/-6.44 + 0.21) rate-10.7+/- 5.47 9.81+/-6.08 0.12) Limitations, reasons for caution design. cycles, bur compared Wider implications findings The provides reassuring data day trigger rates, can negate LH, further studies needed. Trial registration Not applicable