Effects Of OC Pretreatment Prior To GnRH-a Long Protocol On IVF Outcomes In Ovulatory Women

BackgroundGonadotropin releasing hormone agonist(GnRH-a)long protocol is one of the commonest protocol for controlled ovarian hyperstimulation(COH)during in vitro fertilization and embryo transfer(IVF-ET)cycles.GnRH-a down-regulates the function of hypothalamus and pituitary,suppresses the secretion of follicle-stimulating hormone(FSH)and prevents premature surge of luteinizing hormone(LH).Therefore,the development of follicle is completely dependent on exogenous gonadotropin(Gn),which results in synchronization of follicular development and better quality of oocytes.Oral contraceptives(OC)consisting of oestrogen and progestogen can inhibit patients'endogenous production of FSH and LH by negative feedback.Besides,OC suppress gonadal function and abolish LH-surge,which might improve ovarian response to the Gn therapy.Nowadays,only a few researches have investigated functions of OC in long protocol and effects of OC pretreatment prior to long protocol on IVF outcomes remain obscure.ObjectiveThis research is designed to explore the effects of OC pretreatment prior to GnRH-a long protocol on IVF outcomes in ovulatory women.MethodsA total of 2052 women underwent their first fresh IVF/ICSI-ET cycle at Reproductive Hospital Affiliated to Shandong University between 2014 and 2015 were enrolled in this study.According to OC pretreatment or not,patients were divided into OC group(N=1040)or control group(N=1012).The ovarian response,outcomes of fertilization and embryo culture,and pregnancy outcomes were compared between the two groups.Results1.The age,BMI,basal FSH,basal LH,basal AFC were comparable among two groups,and basal E2 was lower in OC group(33.1±12.5 vs.34.6±12.8,P<0.05).2.No differences in Gn starting dose,Gn total dose and Gn duration were observed among two groups.On HCG day,OC group showed lower levels of LH(2.2± 1.0 IU/Lvs.2.5±1.2 IU/L,P<0.001)and thickness of endometrium(11.2±1.7 mm vs.11.4±1.8mm,P<0.05).3.The numbers of oocyte retrieved,cancellation rate were comparable among two groups.The fertilization rate(61.4%vs.58.2%,P<0.001)and numbers of top-quality embryos(4.4±3.0 vs.4.1±2.8,P<0.05)were higher in OC group.4.There were no differences in the rates of pregnancy,pregnancy loss and live birth among two groups.ConclusionsOC pretreatment prior to GnRH-a long protocol did not improve the pregnancy outcome of IVF-ET cycle in ovulatory women,although it was associated with higher fertilization rate and more top-quality embryos.