P–045 A retrospective study on Hyaluronic acid binding sperm selection in ICSI cycles
Authors: Lo J Y , Tee S T 
Published: August 2021

Abstract

Study question
Does Hyaluronic acid(HA) binding sperm selection prior ICSI produce better outcome compare to PVP?

Summary answer
No significant difference in fertilization rate, blastocyst utilization rate, pregnancy rate and miscarriage rate in HA vs PVP group.

What is known already
HA is natural, non-sulphated glycosaminoglycan secretion that abundantly found in the cervical mucus and the cumulus oophorus complex (COC). In in-vivo, HA binding sites on the sperm plasma membrane indicate sperm maturity, mature sperm reaching HA-coated COC can bind and digest HA and subsequent hyperactivation further facilitate fertilization. In IVF, the use of HA tries to mimic in-vivo to select mature sperm with high DNA integrity prior to ICSI. In HA, movement of mature sperm is ‘slowed’ thus allow the selection of sperm to be used in ICSI. Sperm immaturity is known to associated with aneuploidy incidence in the embryos.

Study design, size, duration
ICSI cycle using HA (N = 83) was adapted from January to December 2020 while ICSI cycle using PVP (N = 133) was adapted from January 2018 to December 2019. Mean age of patient were 35.64±4.33 vs 34.15±4.75 for HA vs PVP group respectively. Fertilization rate, blastocyst utilization rate, pregnancy rate and miscarriage rate were recorded. This study included all ICSI cycle and both frozen and fresh embryo transfer data. Surgical retrieved sperm was excluded from this study.

Participants/materials, setting, methods
A 1.5ul of treated spermatozoa suspension was connected with a pipette tip to a 5ul droplet of fresh holding medium (Cook Gamete Buffer). Simultaneously, a 5ul droplet of HA medium (Origio SpermSlow) was connected to the 5ulL droplet of holding medium in a ICSI dish (Sparmed Oosafe) covered with oil (Vitrolife Ovoil). Sperm which were ‘slowed’ in the Sperm slow droplets with normal morphology according to WHO 2010 guideline were selected for ICSI at 400X.

Main results and the role of chance
The fertilization rate of the HA vs PVP- binding sperm are 68.6% vs 66.2%. As for the blastocyst utilisation rate is 61.6% vs 73.22% for HA vs PVP- binding sperm group. Pregnancy and miscarriage rate for HA vs PVP are 42.3% vs 51.5% and 19.4% vs 26.2% respectively.
There was no significant difference in the fertilization rates, blastocysts utilisation rate, pregnancy rate and miscarriage rate between the HA vs PVP- binding sperm groups (P &lt; 0.05). However, a trend of higher pregnancy (51.5% vs 42.3%; P = 0.279) and miscarriage rate were observed in the PVP group (26% vs 19%; P = 0.545) as compared to the HA group, but the difference was not statistically significant. The reason behind this might be the HA assist to select the mature sperm with higher DNA integrity and low frequency of chromosomal aneuploidies which contribute to the lower miscarriage rate in the study.

Limitations, reasons for caution
This is a retrospective study on HA binding sperm selection vs PVP prior to ICSI.
Further research which includes a large number of RCT sample size should be warranted.
Wider implications of the findings: The HA- sperm binding selection ICSI might only be beneficial to certain group of patients (high- DNA fragmentation sperm). A larger RCT study may be necessary to establish a relationship between HA-sperm binding selection vs aneuploidy rate via PGT analysis.

Trial registration number
Not applicable