Preparation of Sperm Fractions and Individual Sperm With Low Levels of Chromosomal Aneuploidies for IVF and ICSI

Abstract

This chapter presents an overview of our ongoing work focusing upon the relationship between diminished sperm maturity and the frequencies of chromosomal aneuploidies, and on the efficiency of the various sperm preparation methods utilized in assisted reproduction for elimination of immature sperm. This chapter will also extend to the major new breakthrough of hyaluronic acid (HA) binding by mature sperm for ICSI sperm selection. First we will discuss research carried out by the Huszar laboratory in the past 15 years relating to objective biochemical markers of sperm function and fertility. Subsequently, we will review the current data and will evaluate the relative utilities of swim-up, gradient centrifugation and HA binding for selection of sperm with low levels of chromosomal aneuploidies and high levels of DNA integrity for IVF and ICSI. The key points to be emphasized are the following: (1) Cytoplasmic retention as a marker of sperm immaturity, and the two-wave expression pattern of the testis specific HspA2 chaperone protein in developing sperm during meiosis and late spermiogenesis. (2) Cellular maturation, plasma membrane remodeling and their contributions to the fertilization function of human sperm. (3) The relationship between sperm immaturity and increased frequencies of chromosomal aneuploidies. (4) The relative efficiencies of density gradient and swim up methodologies in eliminating aneuploid and diploid sperm. (5) The use of HA binding for selection of mature individual sperm with low levels of both chromosomal aneuploidies and DNA degradation.