Can we predict oocyte maturation prior to denudation for intracytoplasmic sperm injection?

Abstract

Intracytoplasmic sperm injection (ICSI) was introduced in 1992 as a method to treat couples with severe male infertility. However, in the last two decades, the use of ICSI has increased substantially even among patients without male factor infertility. In ICSI the oocytes are scrutinized for maturity upon insemination and the immature oocytes are discarded. The aim of the present study was to assess the ability of an experienced embryologist to identify the maturity of the oocytes prior to their denudation.

In the present prospective observational study, four experienced embryologists examined the oocytes prior to their denudation and decided whether the oocytes were mature or immature. Later, the oocytes were denudated and the embryologist again examined the oocytes to confirm their prior assumptions.

483 oocytes were examined by four embryologists. Three hundred and fifty one of the oocytes were mature (72.7%) and 132 were immature (27.3%). The embryologists were able to correctly identify oocytes maturation status in 85.3% of cases. The embryologists were able to correctly identify 90% of the mature oocytes and 72.7% of the immature oocytes. When they assumed that the oocytes were mature they were correct in 89.% of the cases, while only 74.6% of their prediction that the oocytes were immature were true.

To conclude, the embryologists are able to identify the oocytes maturation status before denudation at the majority of the cases. Whenever the oocytes are suspected to be immature, further consideration should be made whether to proceed to ICSI or not.

摘要

胞浆内精子注射（ICSI）是1992年引进的一种治疗严重男性不育夫妇的方法。然而, 在过去二十年中, ICSI的应用率有了显著增长, 甚至在没有男性因素的不孕患者中也是如此。在ICSI中, 仔细检查卵母细胞在受精时是否成熟, 未成熟的卵母细胞被丢弃。本研究的目的是评估有经验的胚胎学家在卵母细胞被剥落之前鉴别其成熟程度的能力。

在目前的前瞻性观察研究中, 4名经验丰富的胚胎学家在卵母细胞被剥落之前对其进行了检查, 以确定卵母细胞是否成熟。卵母细胞被剥除后胚胎学家再次检查卵母细胞以确认其先前的假设。

4个胚胎学家检查了483个卵母细胞, 其中351例卵母细胞成熟（72.7%）, 132例未成熟（27.3%）。胚胎学家能够正确识别85.3%的卵母细胞成熟状态。胚胎学家能够正确识别90%的成熟卵母细胞和72.7%的未成熟卵母细胞。当他们假设卵母细胞已经成熟时, 89%是正确的；而只有74.6%的卵母细胞未成熟的预测是正确的。

综上所述, 在大多数情况下, 胚胎学家能够确定卵母细胞在剥落前的成熟状态。当怀疑卵母细胞不成熟时, 应进一步考虑是否继续进行ICSI。

The Chinese abstracts are translated by Prof. Dr. Xiangyan Ruan and her team: Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing 100026, China.

Keywords:

• ICSI
• oocyte maturation
• oocyte denudation

Authors’ contributions

LB participated in the clinical management and collected the data, performed the statistical evaluations, assisted in writing the paper and edited it in all its revisions. DH collected the data, performed the statistical evaluations, assisted in writing the paper and edited it in all its revisions; participated in the clinical management and edited the paper in all its revisions; participated in the clinical management and edited the paper in all its revisions. RO participated in the clinical management and edited the paper in all its revisions. YY participated in the clinical management and edited the paper in all its revisions. HG participated in the clinical management and edited the paper in all its revisions. CS participated in the clinical management and edited the paper in all its revisions. EZ participated in the clinical management and edited the paper in all its revisions. JH, the principal investigator, designed the study, participated in the clinical management, performed the statistical evaluations, assisted in writing the paper and edited it in all its revisions. All authors read and approved the final manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.