| Polycystic ovarian syndrome(PCOS)is a common gynecological endocrine disease,the age of multiple onset is 17-46 years old,epidemiological survey showed that the incidence of this disease was 6-10%,which was the most common cause of menstrual disorders,amenorrhea and infertility in women of childbearing age,which was accounted for 50-70% of infertile patients with ovulation disorders.Ovulation therapy is an important method for the treatment of infertility in patients with PCOS.At present,the commonly used ovulation drugs are Clomiphene Citrate(CC),gonadotropins(Gn)and letrozole(LE).However,due to the low pregnancy rate,ovarian hyperstimulation syndrome and other obvious defects when taking CC or Gn,thus LE gradually becomes the first-line drug.This study was designed to demonstrate the effect of LE on ovulation and to explore the optimal use of LE as well as to provide evidences for the better use of LE.Objective: The effects on estrogen levels,endometrial thickness and type,follicular development number,ovulation rate and pregnancy rate were observed at different stages of follicular development by using different doses of LE for ovulation induction,the correlation between the variables were analyzed;By comparing with the normal population to clarify whether there was any difference between the two groups and the reason was analyzed to explore the optimal dose of LE in ovulation induction in patients with PCOS.Methods: A total of 80 patients with PCOS treated with LE ovulation treated in the the Reproductive Medicine Center of Chengde City Central Hospital from January 2001 to October 2016 were enrolled,they were randomly divided into two experiment groups of 2.5 mg and 5 mg.At the same time,40 cases with normal ovulation function were selected as the control group.Endometrial thickness was observed on the third day of menstruation by transvaginal B-ultrasound in all cases and estradiol levels were determined.In the experimental group,2.5 and 5mg/d of LE were given for 5 days,and the control group was not intervened.Follicular development and endometrial thickness,type were under continuous monitor,and the number of follicular development was observed,the estradiol levels of 10-12 mm,14-16 mm and 18-20 mm dominant follicles were determined,respectively,ovulation was induced until one mature follicle(follicular diameter ≥ 20 mm)was detected by B-ultrasound,sexual intercourse was on the same day and the next.If the serum human chorionic gonadotropin level was positive 14 days after ovulation,transvaginal ultrasound was given a week later,clinical pregnancy could be diagnosed if transvaginal ultrasound suggested the intrauterine gestational sac or ectopic pregnancy sac.If serum human chorionic gonadotropin level gradually turned to negative,then biochemical pregnancy was diagnosed.The data were analyzed by SPSS 19.0 statistical software.Metrological data is expressed as s,using the variance analysis for comparison.The count data were expressed as a percentage,and the chi-square test was used to compare respectively.P < 0.05 indicated a statistically difference.Result:1 Comparison of estrogen level,endometrial thickness and type: in the three observation windows set in this project,the estrogen level and endometrial thickness in both 2.5 mg and 5 mg LE group were lower than those of the control group,the differences were statistically significant(P < 0.01).Comparison between the two experiment groups found: In the 10-12 mm of dominant follicle,estrogen level in 5.0 mg group was lower than that of 2.5 mg group,the difference was statistically significant(P < 0.05);there was no significant difference in endometrial thickness between 5.0 mg LE and 2.5 mg LE group.In the 14-16 mm of dominant follicle,estrogen level and endometrial thickness in 5.0 mg group were all lower than those of 2.5 mg group,the differences were statistically significant(P < 0.05).In the 18-20 mm of dominant follicle,there were no significant differences in estrogen level and endometrial thickness between 5.0 mg group and 2.5 mg group.Endometrium type on HCG day: C type of endometrium was not found in the three groups,there were no significant differences in A,B types of endometrium among the three groups.2 Comparison of the number of follicular development,follicle maturation time,ovulation rate and pregnancy rate: for the number of follicular development,the control group and 2.5 mg group were all single follicular development,single follicular development in 5.0 mg group was 90%,double follicular development in 5.0 mg group was 7.5%,≥ 3 follicular development in 5.0 mg group was 2.5%,there was significant difference compared with the control group and 2.5 mg group(P < 0.05);for follicle maturation time: there were significant differences among the control group,2.5 mg group and 5.0 mg group(P < 0.01),and there were significant differences between 2.5 mg group and 5.0 mg group(P < 0.05).For the ovulation rate: there was no significant difference in the ovulation rate among the control group,5.0 mg group;and the ovulation rate in 2.5 mg group was higher than that of control group,the difference was statistically differences(P < 0.05).For the pregnancy rate: there was no significant difference among the control group,2.5 mg group and 5.0 mg group.Conclusion: In the process of ovulation induction,the effect of LE on decreasing the estrogen level in the body was very obvious,early low estrogen level led to endometrial hyperplasia unable to reach the normal level,the influence of LE 5 mg group was bigger,endogenous estrogen was secreted by large number of dominant follicle after the withdraw,thus leading to rapid recovery of estrogen level in vivo,there were already no statistically differences in estrogen level and endometrial thickness in 2.5 mg LE and 5.0 mg LE group before ovulation,however,which was still lower than that of the control group.In 2.5 mg LE and 5.0 mg LE group,the endometrium were all A,B types on HCG day,and there was no significant difference compared with that of the control group,which suggested that LE had no significant effect on endometrial morphology.The follicle maturation time in 2.5 mg LE and 5.0 mg LE group was shorter than that of the control group,with the shortest in 5.0 mg group,which suggested that LE could inhibit the estrogen level to further increase FSH and to promote follicular maturation.The control group and 2.5 mg LE group were all the single follicular development,while the ratio of multi follicular development was higher in 5.0 mg group,which suggested that excessive FSH would lead to multiple follicular development at the same time.The ovulation effect of 5 mg LE group was better compared with that of the 2.5 mg group,which had already reach the level of the control group,and there was no statistically difference of pregnancy rate between people using LE and the normal population.Therefore,the effect of LE on ovulation therapy was clear,except for its inhibitory on estrogen level and endometrial thickness,however,it has already reached the requirements of embryo implantation,which led to the result that there was no significant difference of pregnancy rate compared to that of the control group.As the ovulation rate was higher in 5 mg LE group,it should be the optical dose for clinical use,while higher rate of multiple pregnancies should be paid attention to. |
