Usefulness of oocyte accumulation in low ovarian response for PGS

Abstract

This is an observational study of the response to ovarian stimulation and preimplantational genetic screening (PGS) cycles of 188 patients with a foreseen high aneuploid rate, undergoing two or three stimulation cycles (2SC and 3SC) and oocyte vitrification to accumulate oocytes (Accumulation group = 112 patients) compared to patients undergoing one stimulation cycle (1SC Group= 76 patients) and fresh embryo transfer, between January 2011 and July 2014. Accumulation was performed when <10 MII oocytes were retrieved. Oocytes were vitrified for later warming and IVF, when the planned number of oocytes was achieved. After PGS, euploid embryos were transferred. Comparing 2SC Group with 3SC Group, AMH, AFC, number of oocytes retrieved per pick-up and total number of biopsied embryos were significantly higher in the 2SC Group. After chromosome analysis, 18.5% of biopsied embryos were euploid and 58.9% patients reached embryo transfer. There were no differences in pregnancy rates per patient between the 1SC, 2SC and 3SC Groups (36.8%, 34.9% and 31.0%, respectively) or per embryo transfer (59.6, 56.8 and 60%, respectively). In patients with <10 MII oocytes after ovarian stimulation undergoing PGS, accumulating oocytes can render a pregnancy rate per patient and per embryo transfer comparable to those of fresh PGS cycles.

Chinese abstract

本研究对2011年1月到2014年7月188个预计高非整倍体率的患者卵巢刺激反应和植入前基因筛查周期进行观察性研究。这些患者分为积累组(112名患者）和1个刺激周期组(76名患者），积累组通过2个或3个积累周期，卵子通过玻璃化冷冻积累卵母细胞，与1个刺激周期组进行1个刺激周期和新鲜的胚胎移植相比较。当募集到<10MII的卵母细胞时开始积累，当卵母细胞到达预计数量的时候玻璃化冻存，随后IVF。植入前基因筛查后，移植整倍体胚胎。2次刺激组抗苗勒氏管激素、窦卵泡数、每次取卵数和胚胎活检数明显高于3次刺激组。染色体分析后，18.5%的胚胎活检为整倍体，58.9%的患者得到胚胎移植。进行1次、2次和3次的刺激组中的妊娠率没有明显差别（分别为36.8%,,34.9% ,31.0%）胚胎移植率也没有差别(分别为59.6%, 56.8% 和60%)。 卵母细胞小于10MII的患者，移植前基因筛查后进行卵巢刺激与新鲜的植入前基因筛查周期相比，积累的卵母细胞可以提供每个患者和每次胚胎移植的妊娠率。

• Low ovarian response
• oocyte accumulation
• oocyte vitrification
• pregnancy rate
• Preimplantation Genetic Screening

Acknowledgements

This work was performed under the auspices of the Càtedra d’Investigació en Obstetrícia i Ginecologia of the Department of Obstetrics and Gynecology, Hospital Universitari Quirón Dexeus, Universitat Autònoma de Barcelona. We would like to thank Monica Reig for her assistance with the manuscript.

Declaration of interest

The authors declare no conflict of interests. No specific funding was sought for the study. The Dexeus Foundation supported the authors throughout the study period and manuscript preparation.