Total fertilization failure in intra-cytoplasmic sperm injection cycles – classification and management

Abstract

In this retrospective cohort study we intended to propose a classification and preliminary management strategy for couples exhibiting total fertilization failure (TFF) in intra-cytoplasmic sperm injection (ICSI) cycles. Sixteen couples with a total of 27 cycles exhibiting TFF, age <40 and/or more than four M2 oocytes aspirated were enrolled. While TFF occurred in 4.3% of all 3723 ICSI cycles, in women younger than 40 with at least 5 M2 oocytes the TFF rate was 0.7%. Indications for ICSI were severe male factor and unexplained infertility. Of the 16 couples with TFF, 4 demonstrated a single episode of TFF, with either subsequent or former normal fertilizations, thus implying possible sporadic faulty laboratory conditions. Ten couples demonstrated repeated total or very low fertilization rates, hinting at a gamete defect not overcome by ICSI. Two couples experienced TFF in the first and only cycle performed at our unit. We conclude that initial and repeated TFF hints at severe gamete defects for which only donor gametes may prove successful while sporadic TFF events could simply imply a technical modifiable condition.

Chinese abstract

在这项回顾性队列研究中，我们试图提出单精子卵细胞浆内注射周期完全受精失败夫妇的分类及初步管理策略。在本研究中，入组的16对夫妇一共发生了27个周期的完全受精失败，入组夫妇年龄均小于40岁，均取得了超过4个M2期卵母细胞。所有3723例单精子卵细胞胞浆内注射周期完全受精失败的发生率是4.3%，但在年龄小于40岁的妇女且至少取得5个M2期卵母细胞组的完全受精失败的发生率仅为0.7%。单精子胞浆内注射的指征是严重的男性不育因素及不明原因不孕。在发生完全受精失败的16对夫妇中，4对夫妇的完全受精失败是单次事件，她们随后的或者之前的周期中均有正常的受精，这提示是实验室条件改变的偶发失败；10对反复发作或者非常低受精率的夫妇提示了单精子胞浆内注射方法无法解决配子缺陷的问题；另外2对完全受精失败的夫妇在我们实验室有且只做了这一个周期。我们得出这样的结论：初始和重复的完全受精失败暗示严重的配子缺陷，捐赠配子可能是唯一的治疗策略。零星的完全受精失败事件可能只是意味着实验室条件的改变。

• ICSI
• intra-cytoplasmic sperm injection
• total fertilization failure