P-093 A comparison of the effects of IMSI and HOST for sperm selection on morphokinetic parameters and ploidy status in sibling embryos
Authors: Kumtepe Y , Ozkara G , Yelke H.K , Selimoglu S , Soysal E , Yildiz S , Unsal E , Kahraman S 
Published: June 2022

Abstract

Study question
Are hypo-osmotic swelling test (HOST) and intracytoplasmic morphologically selected sperm injection (IMSI) both effective alternative methods for sperm selection?

Summary answer
Similar results were obtained in embryo morphokinetics between HOST and IMSI.

What is known already
HOST is a simple, low-cost and rapid test based on the swelling of the tail of the sperm in a hypoosmotic environment. Less DNA fragmentation, membrane integrity and aneuploidy rates have been found in sperm selected by the HOST method. It also allows identification of viable sperm in a totally immotile sperm sample. IMSI, on the other hand, is a method for identifying the morphologically best sperm using high-magnification microscope. In studies, IMSI has been associated with high fertilization rates. However, it is a time-consuming method that requires expensive equipment.

Study design, size, duration
Time-Lapse Monitoring (TLM)-incubated sibling embryos of 25 male factor patients who applied for ART treatment to Istanbul, Sisli Memorial ART and Genetics Center in 2021 were included into the study. Sibling embryos were grouped according to their sperm selection method. In the IMSI group 170 embryos, in the HOST group 173 embryos were evaluated retrospectively in terms of the morphokinetic parameters, the rates of blastulation, Top- Quality (TQ) and Good Quality (GQ) embryos and euploidy.

Participants/materials, setting, methods
Blastocyst grading was performed according to Gardner’s classification. Blastocysts 3AA,4AA,4AB,4BA,4BB,5AA,5AB,5BA,5BB were accepted as TQ+GQ. Blastulation rates was determined including the embryos at least 2 expansion. PGT-A results were obtained by Next Generation Sequencing(NGS) method. The comparison of the TLM parameters and clinical features of the patients were performed using Student’s t-test. Chi-square test was used for comparing the rates of fertilization, blastulation, TQ+GQ embryo and euploidy in each group.

Main results and the role of chance
No statistical difference was observed between IMSI and HOST groups in terms of morphokinetic parameters (tPN, tPNf, t2, t3, t4, t5, t6, t7, t8, t9, tSC, tM, tSB, tB, tEB) (p &gt; 0.05). There were higher rates of normal fertilization in the HOST group (90.8%) than in the IMSI group (82.4%) and of TQ+GQ embryo (HOST: 50%, IMSI: 47.3%). However, these diffrences were not statistically significant (p &gt; 0.05). There was statistically lower abnormal fertilization rate was found in HOST group (2.3% vs 7.1%, p = 0.038). When PGT-A results were compared (HOST:19 embryos, IMSI: 19), slightly higher results were observed in IMSI group than HOST group ( 63%, 58% respectively) (p &gt; 0.05).

Limitations, reasons for caution
This was a retrospective of a small number of cases.

Wider implications of the findings
The similarity of the outcome in these initial findings studying a small number of cases, suggest that this study should be extended.

Trial registration number
None