Yale University Fertility Centre, 150 Sargent Drive, New Haven, CT 06511, USA.
Reprod Biomed Online. 2007;14 Spec No 1:23-6. doi: 10.1016/S1472-6483(10)61455-1.
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.
体外培养和移植的胚胎绝大多数未能发育成婴儿，这支持了只有一小部分胚胎注定会成为活产儿的概念。胚胎到婴儿的比例如此之低的主要原因之一是，经过胚胎植入前遗传学诊断后，大量胚胎被发现存在染色体失衡。本研究报告了因高龄、反复妊娠丢失或多次体外受精（IVF）周期失败而接受胚胎植入前遗传学筛查（PGS）的患者中，卵子受精后持续妊娠的整体生物学浪费情况。对每个卵子的生物学浪费进行分析显示，在这组患者中，在 333 个卵子中，有 183 个（55.0%）提供了用于活检的胚胎，而这些胚胎中只有 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 的患者的胚胎和卵子中获得的数据支持了这样一种观点，即许多在 IVF 中获得的胚胎和卵子本质上是异常的，因此无法着床。
