Braga Daniela Paes de Almeida, Setti Amanda, Guilherme Patricia, Iaconelli Junior Assumpto, Borges Edson
Fertility Medical Group/FERTGROUP Medicina Reprodutiva, Sao Paulo, Brazil.
Instituto Sapientiae - Centro de Estudos e Pesquisa em Reprodução Assistida.
JBRA Assist Reprod. 2025 Sep 22;29(3):430-436. doi: 10.5935/1518-0557.20250009.
This study explores the influence of seasonal variations on embryo morphokinetics and the outcomes of intracytoplasmic sperm injection (ICSI) cycles.
This retrospective cohort study, performed in a private university-affiliated IVF center from March 2019 - March 2023, included 1,292 intracytoplasmic sperm injection cycles (ICSI) cycles and 8,376 injected oocytes. Cycles and were split depending on the season in which oocyte collection was performed: Spring (n=462 cycles), Summer (n=176 cycles), Autumn (n=258 cycles), and Winter (n=396 cycles). Embryos were cultured in a time-lapse imaging (TLI) incubation system, and embryo morphokinetics and laboratory and clinical outcomes were compared between the groups.
A slower morphokinetic development was observed in embryos derived from cycles performed in the winter compared to those from cycles performed in other seasons, while embryos derived from cycles performed in the summer exhibited faster embryo development. Significantly longer time to complete synchronous divisions t8-t5 (s3) and second (cc2, t3-t2) and third cell cycles (cc3, t5-t3) were also observed among embryos derived from winter cycles, whereas embryos formed during summer presented shorter cycles. Embryos from cycles performed during summer exhibited a significantly higher KIDScore compared to those from winter cycles. Significantly higher implantation rate was observed in cycles performed in the summer, followed by those performed in the spring.
These findings suggest a potential influence of seasonal factors on embryo development and implantation success. The study underscores the importance of considering seasonal variations and their potential biological impacts on assisted reproductive technologies.
本研究探讨季节变化对胚胎形态动力学及卵胞浆内单精子注射（ICSI）周期结局的影响。
这项回顾性队列研究于2019年3月至2023年3月在一所私立大学附属体外受精中心进行，纳入了1292个卵胞浆内单精子注射周期及8376枚注射的卵母细胞。根据卵母细胞采集的季节将周期分为：春季（n = 462个周期）、夏季（n = 176个周期）、秋季（n = 258个周期）和冬季（n = 396个周期）。胚胎在延时成像（TLI）培养系统中培养，比较各组之间的胚胎形态动力学以及实验室和临床结局。
与其他季节进行的周期所产生的胚胎相比，冬季进行的周期所产生的胚胎形态动力学发育较慢，而夏季进行的周期所产生的胚胎发育较快。在冬季周期所产生的胚胎中，还观察到完成同步分裂t8 - t5（s3）以及第二次（cc2，t3 - t2）和第三次细胞周期（cc3，t5 - t3）的时间明显更长，而夏季形成的胚胎周期较短。与冬季周期所产生的胚胎相比，夏季进行的周期所产生的胚胎KIDScore显著更高。夏季进行的周期的着床率显著更高，其次是春季进行的周期。
这些发现表明季节因素对胚胎发育和着床成功具有潜在影响。该研究强调了考虑季节变化及其对辅助生殖技术潜在生物学影响的重要性。
