Sperm chromatin maturity and integrity correlated to zygote development in ICSI program

ABSTRACT

This study aimed to evaluate sperm chromatin maturity and integrity of that injected into good-quality oocytes in an in vitro fertilization-intra cytoplasmic sperm injection (IVF-ICSI) program. A cut-off value of sperm chromatin maturity and integrity was developed as a function of their correlation to the zygote development, i.e., embryo formation and cleavage rate. The study assessed sperm chromatin maturity using aniline blue (AB) staining, whereas toluidine blue (TB) staining was used to assess sperm chromatin integrity. Ejaculates from 59 patients undergoing ICSI and 46 fertile normozoospermic donors for determination of normal values of sperm chromatin status were used in this study. Embryo formation and cleavage rates were observed for the period of 3 days after ICSI. There was a significant difference in the percentage of sperm with mature chromatin between ejaculate from ICSI patients and fertile donor (p=0.020); while there was no significant difference in sperm chromatin integrity of both samples (p=0.120). There was no significant correlation between sperm chromatin maturity and either embryo formation or cleavage rate; as well as sperm chromatin integrity to both parameters of zygote development (p>0.05). Furthermore, we found that the cut-off value of sperm chromatin maturity and integrity of the fertile normozoospermic ejaculates were 87.2% and 80.2%, respectively. Using the cut-offs, we found that low sperm chromatin maturity at the level of <87% correlated significantly with the cleavage rate of the zygote (p=0.022; r=0.371); whereas poor sperm chromatin integrity at the level of <80% correlated with embryo formation (p=0.048; r=0,485). In conclusion, this study showed that poor maturity and integrity of sperm chromatin (AB<87% and TB<80%, respectively), could affect zygote development following ICSI.

Abbreviations: AB: aniline blue; CMA3: chromomycin A3; ICSI: intra cytoplasmic sperm injection; IVF: in vitro fertilization; PBS: phosphate buffer saline; SPSS: Statistical Package for Social Science; TB: toluidine blue; WHO: World Health Organization

KEYWORDS:

• Integrity
• IVF-ICSI
• maturity
• sperm chromatin
• zygote development

Acknowledgments

The authors thank Amalia Shadrina, MD from the Faculty of Medicine University of Indonesia - Cipto Mangunkusumo Hospital for help in editing the manuscript, and Hans-Joachim Freisleben from the Faculty of Medicine University of Indonesia, and Liana W. Susanto, MBiomed, of Dexa Medica, Indonesia, for help revising the manuscript.

Declaration of interest

This study was supported by International Collaborative Research Fund, in Directorate for Higher Education of Indonesian Ministry for Education and Culture of Republic of Indonesia. The authors report no declarations of interest.

Additional information

Notes on contributors

Asmarinah

All authors contributed similarly, while each had a different main responsibility. Conceived and designed the study as well as drafted the manuscript: A; Performed the study and analyzed the data: AS, LAU; Recruited the subjects and carried out semen analysis: SWL; Recruited the subjects and performed ICSI program: EM, AH; Recruited the subjects for IVF program and helped in drafting the manuscript: AH. Participated in study design and developed the sperm chromatin assay: AP-D.