Correlation Between Neutrophil To Lymphocyte Ratio And Ovarian Response Index Of IVF In Patients With PCOS

Objective:The neutrophil to lymphocyte ratio（NLR）in peripheral blood can reflect the level of chronic inflammation,and recent studies have shown the presence of chronic low-grade inflammation in patients with polycystic ovary syndrome（PCOS）,but the relationship between the two is unclear.Few studies have analyzed the ovarian response indicators of pre-and post-ovulatory NLR in PCOS patients undergoing in vitro fertilization（IVF）.The main objectives of this study were,on the one hand,to analyze the changes in NLR levels before and after ovulation promotion in a population of PCOS patients undergoing IVF treatment.On the other hand,to analyze the correlation between NLR and ovarian response indicators and IVF laboratory outcomes in a population of PCOS patients undergoing IVF.Methods:A retrospective cohort analysis was performed on clinical data from 227 patients（aged between 20 and 37 years）with PCOS who attended the Reproductive Medicine Center at Affiliated Hospital of Jining Medical University and underwent IVF from January 2018 to January 2021.The main indicators included:patients’age,body mass index（BMI）,type of infertility,duration of infertility,endocrine hormone levels such as follicle-stimulating hormone（FSH）,luteinizing hormone（LH）,prolactin（PRL）,testosterone（T）,estradiol（E₂）,progesterone（P）,thyroid-stimulating hormone（TSH）,anti-Müllerian hormone（AMH）,antral follicle count（AFC）,total gonadotropin（Gn）dose,total number of oocytes gained,number of mature oocytes,number of normal fertilizations,number of normal oogenesis,number of good quality embryos,pre-and post-ovulatory neutrophil（N）counts and lymphocyte（L）counts before and after ovulation.Pre-and post-ovulation NLR were defined as NLR1 and NLR2,respectively,and patients were divided into low and high NLR groups based on the median NLR.Subtype variables were expressed as number of cases with percentages,while other continuous-type variables were expressed as mean±standard deviation.First,based on a brief summary and comparison of data from the study population,correlations between NLR1,NLR2,and other relevant clinical indicators and ovarian response indicators（total number of oocytes gained and number of high-quality embryos）were derived using univariate correlation analysis.Then,after adjusting for relevant confounders,multiple regression analysis was used to test whether NLR1and NLR2 levels were independently correlated with the total number of oocytes gained and the number of high-quality embryos.Finally,smoothed curve fitting was used to visualize the relationship between NLR1 and NLR2 levels and ovarian response indicators,and a threshold effect analysis was performed to demonstrate whether there was a significant trend of correlation between the variables.Results:Based on the baseline data,it can be seen that during ovulation promotion,NLR2 was significantly higher than NLR1（3.30±1.46 vs 1.96±0.84,P<0.001）,with N predominantly elevated;the low NLR1（NLR1<1.76）group had more AFC than the high NLR1（NLR1≥1.76）group（31.51±8.53 VS 28.77±8.62,P<0.05）and less Gn dosage（2029.87±802.46 VS 2317.43±1012.08,P<0.05）;total number of oocytes gained,number of mature oocytes,number of normal fertilization,number of normal oocyts cleavage,number of high quality embryos,and E₂level on trigger day were significantly lower in the low NLR2（NLR2<3.13）group than in the high NLR2（NLR2≥3.13）group（NLR2≥3.13）group,and the results were statistically significant.After dividing the patients into obese and non-obese groups for analysis,L1 and L2were higher in the obese group（BMI≥25 kg/m2）than in the non-obese group（BMI<25 kg/m2）（P<0.05）,while NLR1 and NLR2 were not significantly different between the two groups（P>0.05）.Univariate analysis concluded that BMI and FSH were significantly negatively correlated with total number of oocytes gained（P<0.05）,T,AMH,NLR2,and trigger day E₂were significantly positively correlated with total number of oocytes gained（P<0.05）;BMI and FSH were significantly negatively correlated with number of quality embryos（P<0.05）,and T,AMH,E₂level on trigger day,total number of oocytes gained,number of mature oocytes,number of normal oocytes cleaved,and The number of normal fertilization was positively and significantly correlated with the number of good quality embryos（P<0.05）.Further multiple regression analysis showed that after adjusting for relevant variables,NLR1 still showed no significant correlation with the total number of oocytes gained and the number of good quality embryos,while NLR2 showed a significant positive correlation with the total number of oocytes gained.The results of smoothing curve fitting and threshold effect analysis showed that the relationships between NLR1 and total number of oocytes gained,between NLR1 and number of quality embryos were linear,with no inflection point and no statistically significant linear trend;a significant positive linear correlation between NLR2 and total number of oocytes gained;the relationship between NLR2 and number of quality embryos was a curve that first increased and then decreased,with a fold point of 3.37,that is,for NLR2<3.37,the number of quality embryos increased by 0.52 per unit increase,and this increase was not significant（P=0.133）;when NLR2>3.37,the number of quality embryos decreased by 0.49 per unit increase,and this decrease was significant（P=0.008）.Conclusion:The present study showed that NLR values were significantly higher after ovulation promotion compared with those before ovulation promotion,with a predominant increase in N,suggesting that the ovulation promotion process may have a greater effect on N.Post-ovulation NLR was significantly and positively correlated with the total number of oocytes gained in PCOS patients treated with IVF.A curvilinear relationship between post-ovulatory NLR and the number of quality embryos in PCOS patients undergoing IVF treatment was observed,with an expected value of 9.09,95%CI（8.01,10.17）.These results are expected to be indicative for PCOS patients treated with IVF-ET.