Objective: To investigate the effect of follicular size on the clinical outcomes of frozen-thawed embryo transfer induced by human chorionic gonadotropin (hCG) of natural cycles on ovulation. Methods: Clinical data of 427 cycles of frozen-thawed single blastocyst transfer in Nanjing Drum Tower Hospital from January 2016 to December 2019 were retrospectively analyzed. The patients were divided into 15-16 mm group (15≤diameter≤16 mm, n=66), 16-17 mm group (16<diameter≤17 mm, n=101), 17-18 mm group (17<diameter≤18 mm, n=125), 18-20 mm group (18<diameter≤20 mm, n=109),>20 mm group (diameter>20 mm, n=26), according to the maximum follicle diameter on the induction day of hCG ovulation induction. The estradiol and luteinizing hormone (LH) levels, and clinical pregnancy rate, abortion rate and live birth rate were compared in five groups. Results: There were statistically significant differences in estradiol and LH levels among the five groups on the day of hCG induction (all P<0.05). Estradiol levels in 15-16 mm group to >20 mm group gradually increased on the day of hCG induction, and estradiol level in 15-16 mm group was significantly lower than those in 17-18 mm group, 18-20 mm group and >20 mm group (median: 1 002.3 vs 1 103.3 vs 1 171.2 vs 1 539.0 pmol/L), with statistical significances (P=0.034, P<0.001, P=0.002). On the day of hCG induction, LH levels in 15-16 mm group to >20 mm group showed a decreasing trend, and LH level in 15-16 mm group was significantly higher than those in 17-18 mm group and >20 mm group (median: 37.73 vs 28.24 vs 24.11 U/L), with statistically significant differences (P=0.007, P=0.006). There were no significant differences in clinical pregnancy rate, abortion rate and live birth rate in 15-16 mm group to >20 mm group (all P>0.05). Conclusion: In the natural cycle protocol of hCG induced ovulation, the small follicle group could achieve similar clinical outcomes compared with normal sized follicles in the single blastocyst transfer of frozen-thawed embryos.
目的： 探讨自然周期使用人绒毛膜促性腺激素（hCG）诱导排卵日卵泡大小对冻融胚胎移植临床结局的影响。 方法： 回顾性分析2016年1月至2019年12月在南京大学医学院附属鼓楼医院接受冻融单囊胚移植患者，采用hCG诱导排卵的自然周期方案共427个周期的临床资料，根据hCG诱导排卵日最大卵泡直径分为15~16 mm组（≥15且≤16 mm，n=66），16~17 mm组（>16且≤17 mm，n=101），17~18 mm组（>17且≤18 mm，n=125），18~20 mm组（>18且≤20 mm，n=109），>20 mm组（>20 mm，n=26），比较各组的hCG诱导排卵日雌二醇和黄体生成素（LH）水平，并对比各组的临床妊娠率、流产率及活产率。 结果： hCG诱导排卵日雌二醇及LH水平5组患者总体比较，差异均有统计学意义（P均<0.05）。5组（15~16 mm组至>20 mm组）hCG诱导排卵日雌二醇水平逐渐升高；15~16 mm组雌二醇水平（中位数为1 002.3 pmol/L）明显低于17~18 mm组、18~20 mm组、>20 mm组（中位数分别为1 103.3、1 171.2、1 539.0 pmol/L），两两比较，差异均有统计学意义（P=0.034、P<0.001、P=0.002）。5组（15~16 mm组至>20 mm组）hCG诱导排卵日LH水平呈降低趋势；15~16 mm组LH水平（中位数为37.73 U/L）明显高于17~18 mm组、>20 mm组（中位数分别为28.24、24.11 U/L），两两比较，差异均有统计学意义（P=0.007、P=0.006）。5组患者的临床妊娠率、流产率及活产率分别比较，差异均无统计学意义（P均>0.05）。 结论： 在冻融胚胎单囊胚移植，使用hCG诱导排卵的自然周期方案中，小卵泡排卵者能够得到与正常大小卵泡者相似的临床结局。.