A new real-time morphology classification for human spermatozoa: a link for fertilization and improved embryo quality

Objective

To understand the correlation between normalcy of the sperm, fertilization, and early embryo development, and to establish a detailed classification scoring scale for the individual spermatozoon with the highest predictive fertilizing potential in real time during intracytoplasmic sperm injection (ICSI).

Design

A retrospective and analysis.

Setting

Laboratory Drouot.

Patient(s)

27 couples with male factor infertility referred for ICSI treatment.

Intervention(s)

Before ICSI, motile spermatozoa were scored after aspiration.

Main Outcome Measure(s)

Oocyte fertilization, embryo development and morphology, outcome of scored motile injected spermatozoa.

Result(s)

Our suggested formula is (Normal head score = 2) + (Lack of vacuole score = 3) + (Normal base score = 1) = (Total score = 6) for a morphologic “normal top” spermatozoon, calculated with the major criteria affecting the outcome of ICSI. We take into account the normalcy of head size and shape, the base of the head, and the lack of vacuoles. Our scoring of three classes of injected spermatozoa revealed a statistically significant difference in fertilization rate: 39 out of 46 (84%), 94 out of 128 (73%), and 27 out of 44 (61%), respectively. Our examination of the contribution of maternal age in correlation to sperm score revealed a distinction between oocytes originating from women younger than 30 years and oocytes from women aged 30 years and older.

Conclusion(s)

Our suggested classification provides allows the best spermatozoon to be chosen for ICSI, particularly for oocytes from women aged 30 years and older.

Key Words: Sperm morphology, motile spermatozoon, ICSI, real-time sperm scoring scale, fertilization potential, embryo morphology, age-related fertilization