Analysis Of Factors Affecting Pregnancy Outcome Of Frozen Embryo Transfer Cycle In Patients With Polycystic Ovary Syndrome

Objective:This study aims to find and quantify the risk factors th at may lead to different pregnancy outcomes in patients with PCOS thr ough case-control studies,and then provide a basis for clinical treatmen t.Methods:The study included 988 patients who were infertile due t o PCOS and underwent the first cycle of frozen thawed embryo transfe r at the Second Hospital of Hebei Medical University.All patients unde rwent frozen thawed embryo transfer after January 1,2018,and comple ted follow-up survey.They were divided into 6 groups according to thei r pregnancy outcome:Group of PCOS clinical pregnancy（n=595）,Grou p of PCOS non-clinical pregnancy（n=393）;Group of PCOS live birth（n=525）,Group of PCOS pregnancy loss（n=463）;Group of PCOS abort ion（n=70）,Group of PCOS continued pregnancy（n=525）.Their age wa s collected and compared,as well as infertility duration,body mass inde x（BMI）,Estradiol（E₂）,luteinizing hormone（LH）,progesterone（P）,test osterone（T）,anti-Mullerian Tube hormone（AMH）,thyroid-stimulating h ormone（TSH）,free triiodothyronine（FT3）,free thyroxine（FT4）,total c holesterol（TC）,triglycerides（TG）,high-density lipoprotein（HDLC）,low-density lipoprotein（LDLC）,apolipoprotein A1（Apo-A1）,apolipoprotein B（Apo B）,lipoprotein a（Lp（a））,fasting blood glucose level（GLU）),the endometrial thickness on the day of transfer,the number of high-q uality embryos and the number of embryos transferred.Adjusted logistic regression analysis was used to obtain independent risk factors that aff ect the pregnancy outcome of PCOS patients,the smooth-curve fitting a nd threshold effect analysis were used to further quantify their impact o n pregnancy outcomes.Results:In PCOS patients who received frozen thawed embryo transfer,the endometrial thickness on the day of transfer was an independent risk factor affecting their clinical pregnancy rate（OR=1.699,95%CI（1.022,2.825）,P<0.05）,The result should that when the endometrial thickness was less than9.8mm on the day of transplantation,the clinical pregnancy rate increases by69.9%for every 1mm increase in the endometrial thickness;after the endometrial thickness exceeds 9.8mm,the clinical pregnancy rate does not increase significantly.FSH（OR=1.176,95%CI（1.082,1.279）,P<0.05）,LDLC（OR=1.252,95%CI（1.033,1.516）,P<0.05）,LH（OR=0.944,95%CI（0.926,0.963）,P<0.05）and hyperlipidemia（OR=2.33,95%CI（1.619,3.355）,P<0.05）were independent factors affecting the live birth rate of PCOS patients.When FSH<4.97 m IU/m L,every 1m IU/m L increased in FSH would reduce the live birth rate by 42.8%;when FSH between 4.97 to 10m IU/m L,every 1m IU/m L increased in FSH would increase the live birth rate by 26.2%;after FSH exceeds 10m IU/m L,the live birth rate does not change significantly.When LDLC was less than 1.8 mmol/L,for every 1 mmol/L increased in LDLC,the live birth rate increased by 5947%;when LDLC was between1.8-4 mmol/L,for every 1 mmol/L increased in LDLC,the live birth rate decreased by 35.4%;When LDLC≥4 mmol/L,with the increased of LDLC,there was no statistically significant change in live birth rate.The impact of LH level on the live birth rate showed an upward trend,followed by a downward trend.When LH<4 m IU/m L,for every 1 m IU/m L increased in LH,the live birth rate increased by 28.7%;when LH>4m IU/m L,LH for every increase of 1 m IU/m L,the live birth rate decreased by 6.2%.BMI（OR=1.076,95%CI（1.003,1.154）,P<0.05）and the number of 2 embryos transferred（OR=0.372,95%CI（0.196,0.706）,P<0.05）were independent of the abortion rate in PCOS patients Influencing factors.The rate of continued pregnancy in those who have transferred two embryos is higher than that in those who have transferred a single embryo.When BMI<25 kg/m² and BMI>27.89 kg/m²,the abortion rate did not change significantly with the change of BMI（P>0.05）.When BMI was between 25-27.89kg/m²,BMI increased by 1 kg/m²,the abortion rate increased by 107.4%（P<0.05）.Conclusions:Endometrial thickness on the day of transfer can be used as an index to predict whether patients with PCOS were clinically pregnancy,but it had no significant effect on the live birth rate and a bortion rate.FSH,LDLC and hyperlipidemia were risk factors affecting live birth in PCOS patients,while LH level was a protective factor affe cting live birth in PCOS patients.which suggested that clinicians should try to control the levels of FSH and LH in PCOS patients and activel y correct dyslipidemia.The rate of continued pregnancy in those who h ave transferred two embryos is higher than that in those who have trans ferred a single embryo.BMI had a significant impact on the abortion ra te of overweight PCOS patients,but had no significant effect on the ab ortion rate of PCOS patients with normal BMI.After the weight level o f PCOS patients reached the obesity standard,with the increase of the patients BMI,the change of their abortion rate was not statistically sign ificant.It is suggested that the weight loss goal of this part of patients should be at least reduced to 27.89kg/m² before it may have a positive impact on the pregnancy outcome.