The Predictive Effect Of Blood Lipid Level Combined With FORT On IVF/ICSI Outcome And The Characteristics Of Intestinal Flora In PCOS Patients

Polycystic ovary syndrome（PCOS）is a highly heterogeneous chronic metabolic disorder affecting about 5%to 20%of women of childbearing age worldwide.PCOS is the main cause of anovulatory infertility.About 28%of patients need assisted reproductive technology（ART）.These patients have a high response to ovulation-promoting drugs,and the number of oocytes obtained in a single cycle is higher than that of normal ovarian response.However,due to the large increase in the proportion of immature oocytes,the fertilization rate of oocytes and the number of transplantable embryos decrease,and ultimately affect the outcome of assisted reproduction.Studies have shown that abnormal lipid metabolism is the most common type of metabolic disorders in PCOS patients,and can affect the quality of oocytes by changing the oocytes themselves and their microenvironment,and have a negative impact on the outcome of assisted pregnancy.Follicular output rate（FORT）,as a quantitative index to predict ovarian response,has also been recognized by some scholars.Therefore,whether blood lipid combined with FORT can better predict ovarian response and ART assisted pregnancy outcome,this study was to explore.In addition,whether lipid metabolism is related to the changes of intestinal flora in PCOS patients is also verified in this study.Part I Predictive effect of blood lipid level combined with FORT on IVF/ICSI outcome in PCOS patientsObjective:To investigate the predictive effect of blood lipid level combined with FORT on IVF/ICSI outcome in PCOS patients.Methods:The clinical data of 313 patients with PCOS and 392 patients with tubal factor infertility（control group）who underwent IVF/ICSI-ET for the first time in the Reproductive Center of the First Hospital of Lanzhou University from June2021 to June 2022 were collected.Firstly,the clinical data,blood lipids and FORT were compared between the PCOS group and the control group.Secondly,PCOS patients were divided into two groups according to blood lipid levels:normal blood lipid group and abnormal blood lipid group.Thirdly,PCOS patients were divided into low FORT group,medium FORT group and high FORT group according to the FORT value,and the blood lipid level,FORT and pregnancy outcome related indicators of each group were further analyzed and compared.Finally,the correlation between blood lipids and FORT in PCOS patients and its effect on pregnancy outcome were analyzed.Results:1.Compared with the control group,the levels of triglyceride（TG）,total cholesterol（TC）and low density lipoprotein（LDL）in PCOS group were significantly increased（P<0.05）,while high density lipoprotein（HDL）was significantly decreased（P<0.05）.The total days of Gn administration,E₂ on HCG-day,P on HCG-day,preovulatory mature follicle count（PFC）,total number of MII,total number of 2PN,number of high-quality embryos and antral follicle count（AFC）in the PCOS group were significantly increased（P<0.05）,while the total amount of Gn administration,number of available embryos,high-quality embryo rate,oocyte utilization rate and FORT were significantly decreased（P<0.05）.The live birth rate of PCOS group was significantly decreased,while the early abortion rate was significantly increased（P<0.05）.2.Patients in the PCOS group were stratified according to blood lipid levels.Compared with the normal blood lipid group,the total number of PFC,MII,2PN,high-quality embryo rate,egg utilization rate,FORT,embryo implantation rate,clinical pregnancy rate and live birth rate in the dyslipidemia group were significantly lower（P<0.05）,while AFC,biochemical pregnancy rate and early abortion rate were significantly higher（P<0.05）.3.Patients in PCOS group were stratified according to FORT value.TG and TC decreased significantly with the increase of FORT（P<0.05）,while HDL increased significantly（P<0.05）.The total number of PFC,MII and 2PN increased significantly with the increase of FORT（P<0.05）.The number of high-quality embryos and live birth rate in the low FORT group were significantly lower than those in the middle and high FORT groups（P<0.05）.The biochemical pregnancy rate and early abortion rate in the low FORT group were significantly higher than those in the middle and high FORT groups（P<0.05）.There was no significant difference in the above indicators between the middle and high FORT groups（P>0.05）.4.In the PCOS group,TG,TC,LDL were negatively correlated with FORT（P<0.05）,and HDL was positively correlated with FORT（P<0.05）.TG,TC and LDL were negatively correlated with the number of high-quality embryos and live birth rate（P<0.05）,and FORT and HDL were positively correlated with the number of high-quality embryos and live birth rate（P<0.05）.5.Multiple linear regression analysis showed that TG,TC,LDL and the number of high-quality embryos in PCOS group（B=-0.826,P=0.001;B=-0.249,P=0.001）;the median FORT was positively correlated with the number of high-quality embryos（B=0.022,P=0.001）.6.Binary logistic regression analysis showed that TG and LDL were independent risk factors for live births[OR=0.664,95%CI（0.015～0.664）],[OR=0.532,95%CI（0.003～0.532）],and FORT was an independent protective factor for live births[OR=1.018,95%CI（1.018～1.010）].Conclusion:High levels of TC,TG,LDL and low levels of HDL in PCOS patients can reduce the number of high-quality embryos and reduce the live birth rate;FORT can well evaluate the ovarian response to Gn drugs and pregnancy outcomes in PCOS patients,and when FORT is controlled at a medium level,the best assisted pregnancy outcome can be obtained;TG,TC,LDL,HDL in PCOS patients are correlated with FORT.TG,LDL combined with FORT can predict the ovarian response and pregnancy outcome of PCOS patients,and can be used to guide the clinical treatment of PCOS patients.Part II Characteristic analysis of intestinal flora in PCOS patients and its correlation with blood lipidsObjective:To analyze the characteristics of intestinal flora in PCOS patients based on 16S r RNA technology,and to clarify the changes of intestinal flora structure and its correlation with blood lipids.Methods:From September 2020 to December 2020,27 PCOS patients who visited the outpatient clinic of the Reproductive Center of the First Hospital of Lanzhou University were selected and divided into BMI normal group（n=9）and BMI overweight group（n=18）according to BMI level.Healthy women of childbearing age who underwent pregnancy preparation examination during the same period were included as the control group（n=10）.The 16S r RNA sequencing technology was used to analyze the bacterial characteristics of each fecal sample and analyze its correlation with blood lipids.Results:1.Compared with the control group,the levels of TC,TG and LDL in the PCOS group increased,and HDL decreased（P<0.05）,and the changes in PCOS patients with BMI overweight were the most significant（P<0.05）.Theαdiversity of PCOS group was lower than that of control group,but the difference was not significant（P>0.05）.βdiversity analysis showed that the difference between the three groups was significantly smaller than that between the groups（P<0.05）,and the grouping was more reasonable.The intestinal flora of each sample was mainly composed of Firmicutes,Bacteroidetes,Proteobacteria and Actinobacteria,accounting for more than 95%of the total flora.Compared with the control group,the abundance of Firmicutes in BMI overweight group and BMI normal group was significantly decreased（P<0.05）,while the abundance of Bacteroidetes in BMI normal group and Proteobacteria in BMI overweight group was significantly increased（P<0.05）.4.In PCOS group,Bacteroidetes and Proteobacteria were positively correlated with TC,TG and BMI（P<0.05）,Verrucomicrobia and Desulfobacteria were positively correlated with TG（P<0.05）,Bacteroidetes was negatively correlated with HDL（P<0.05）.Conclusion:The structure of intestinal flora in PCOS group was significantly different from that in control group,showing the decrease of bacterial diversity,the decrease of Firmicutes and the increase of Bacteroidetes,especially in PCOS patients with BMI overweight.Bacteroidetes and Proteobacteria were positively correlated with TC,TG and BMI,suggesting that the changes of intestinal flora structure,lipid metabolism disorder and the increase of BMI may affect each other in PCOS patients,and promote or aggravate the progression of PCOS disease.