Patrizio P, Bianchi V, Lalioti M D, Gerasimova T, Sakkas D
Yale University Fertility Centre, 150 Sargent Drive, New Haven, CT 06511, USA.
Reprod Biomed Online. 2007 Jan;14(1):92-5. doi: 10.1016/s1472-6483(10)60769-9.
The vast majority of embryos produced in vitro and transferred fail to develop into an infant, supporting the concept that only a small fraction of embryos is destined to become a live birth. One of the main reasons for such a low embryo-to-infant ratio is the remarkably high number of embryos that after preimplantation genetic diagnosis are found to have a chromosome imbalance. This study reports the overall biological wastage from oocytes inseminated to ongoing pregnancies in patients undergoing preimplantation genetic screening (PGS) because of advanced age, recurrent pregnancy losses or multiple failed IVF cycles. The analysis of biological wastage per oocyte showed that in this cohort of patients, of 333 eggs inseminated, 183 (55.0%) provided embryos for biopsy, and of these, only 33 (18.0% per embryo and 9.9% per oocyte) were normal. A total of 26 embryos were suitable for transfer (14% per embryo and 7.8% per oocyte), but only five (1.5%) implanted and three (1.0%) resulted in live births. In conclusion, there is enormous biological wastage during assisted reproduction, and the data obtained from both embryos and oocytes of patients undergoing PGS support the concept that many embryos and eggs obtained during IVF are intrinsically abnormal and thus fail to implant.
绝大多数体外产生并移植的胚胎无法发育成婴儿，这支持了只有一小部分胚胎注定会活产的概念。胚胎与婴儿比例如此之低的主要原因之一是，在植入前基因诊断后发现有染色体失衡的胚胎数量非常多。本研究报告了因高龄、复发性流产或多次体外受精周期失败而接受植入前基因筛查（PGS）的患者，从卵子受精到持续妊娠过程中的总体生物学浪费情况。对每个卵子的生物学浪费情况分析表明，在该患者队列中，333个受精卵子中有183个（55.0%）提供了用于活检的胚胎，其中只有33个（每个胚胎18.0%，每个卵子9.9%）是正常的。共有26个胚胎适合移植（每个胚胎14%，每个卵子7.8%），但只有5个（1.5%）着床，3个（1.0%）活产。总之，辅助生殖过程中存在巨大的生物学浪费，从接受PGS患者的胚胎和卵子获得的数据支持了这样一个概念，即体外受精过程中获得的许多胚胎和卵子本质上是异常的，因此无法着床。
