摘要
Background:To investigate the factors associating with the cumulative clinical pregnancy outcome of in vitro fertilization-embryo transfer(IVF-ET)in women aged 35 years and older with normal ovarian reserve.Methods:A total of 358 patients undergoing IVF-ET at the Department of Reproductive Medicine,the First Affiliated Hospital of Xinjiang Medical University between January 2014 and June 2016 were analyzed by the Kaplan-Meier method and Cox proportional hazards model.Results:The probability of pregnancy in women 35-37 years of age and 38-40 years of age was 75.9%(95%confidence interval[CI]:75.1%-76.7%)and 66.9%(95%CI:65.6%-68.2%),respectively,and it was 37.8%(95%CI:34.7%-41.1%)in women aged 40 years and older.Univariate analysis(hazard ratio[HR]:2.50,95%CI:1.647-3.774)and multivariate analysis(HR:2.17,95%CI:1.427-3.268)showed a correlation between the number of retrieved oocytes and successful pregnancy.Conclusions:The number of retrieved oocytes plays a key role in the pregnancy outcome of women aged 35 years and older with normal ovarian reserve.We recommend the number of retrieved oocytes be increased for women aged 35 years and older with normal ovarian reserve.