Use of hyaluronic acid for sperm immobilisation and selection before intracytoplasmic sperm injection: A systematic review and meta-analysis

Table 2 Treatment protocol adopted in included trials

Ref.	HA group	PVP group
Balaban et al[16]	Oocytes were injected with sperm exposed to, SpermCatch (NidaCon International, Gothenburg, Sweden), a viscous liquid containing hyaluronate and human serum albumin	Oocytes were injected with sperm exposed to the PVP-containing product
Barak et al[5]	Sperm suspension which contained motile spermatozoa was introduced into the center of viscous suspension of hyaluronic acid. Motility of the sperm cells was slowed down. After breaking the sperm tail with the injection pipette, the spermatozoa were injected into the oocytes	MII oocytes were injected with sperm cells which were immobilized and aspirated for injection in 10% PVP solution
Castillo-Baso et al[17]	Sperm selected by PICSI (Mid Atlantic Diag. Inc.)	Sperm selected by conventional ICSI
Gandhi et al[19]	2 μL droplet with suspension of spermatozoa was placed to a 5 μL droplet of HA-containing medium (SpermSlow; MediCult, Jyllinge, Denmark) and incubated for 15 min at 37 °C under oil. Spermatozoa bound to HA in the junction of the two droplets were identified and carefully detached by injecting pipette (ICSI Micropipette; TPC, Thebarton, Adelaide, South Australia) and subsequently injected into a MII oocyte	Before injection, 3 μL of sperm suspension was transferred to 7 μL of 7% polyvinylpyrrolidone (PVP; SAGE) solution to remove debris and get better control. Spermatozoa with best morphology were selected for injection into a MII oocytes using inverted microscope equipped with micromanipulators
Gandhi et al[19]	Donated oocytes to avoid female infertility as a bias factor, randomly carried out with SpermSlow for sperm selection	Donated oocytes to avoid female infertility as a bias factor randomly carried out with PVP for sperm selection
Majumdar et al[20]	Sterile PICSI dishes (Origio MidAtlantic Devices, United States) with three hyaluronan microdots attached to the interior bottom, were used. 10 μL droplets of culture medium (GMOPS, Vitrolife) were placed over the hyaluronan microdots and an elongated 10 μL drop of PVP was made below the drops, before covering the dish with oil. 1-2 μL of sperm suspension was then added to the hyaluronan microdot containing droplets. After 5 min of incubation at 37 °C, HA bound sperm with normal morphology were removed with an injecting micropipette (TPC, Australia) to the adjacent PVP droplet, immobilized and subsequently injected	An elongated 10 μL poly vinyl pyrolidone drop (PVP, Medicult, Denmark) under oil, was used to select spermatozoa with normal morphology for subsequent injection
Moon et al[21]	ICSI were performed with husband spermatozoa which immobilized in 2.5 mg/mL hyaluronic acid	ICSI were performed with husband spermatozoa which immobilized in 5% PVP
Parmegiani et al[22]	Spermatozoa were selected for their ability to bind to HA: A 2-mL droplet with suspension of spermatozoa was connected with a pipette tip to a 5-mL droplet of HA-containing medium (SpermSlow; MediCult) and allowed to incubate for 15 min at 37 °C under oil (Liquid Paraffin; MediCult). Spermatozoa bound to HA in the junction zone of the two droplets were selected and easily detached by injecting pipette (ICSI Micropipette; Humagen Fertility Diagnostics) and subsequently injected into oocytes	Conventional PVP-ICSI procedure
Worrilow et al[24]	At the time of injection, drops were prepared in the lid of a Falcon Petri dish (353004; Becton Dickinson, Franklin Lakes, United States). In the middle of the dish a 10 μL drop of Spermslow (Medicult) and a 10 μL Flushing Medium drop (Medicult) were connected by a 3-4 mm junction bridge of medium and consecutively encircled by five 10 μL drops of Flushing medium. This setup was covered with liquid paraffin (Medicult). A 2 μL volume of prepared semen was added to the medium part of the Spermslow/Flushing medium central mixture. The spermatozoa were allowed to migrate towards the junction for a period of 15-20 min at 37 °C. Spermatozoa were carefully selected near the junction between the sperm droplet and the SpermSlow droplet	Non-bound, forward-moving spermatozoa were taken from the SpermSlow droplet
Worrilow et al[24]	PICSI embryos created using Hyaluron Bond-sperm	Standard sperm selection criteria
Worrilow et al[25]	The final sperm suspension of HYAL patients was placed upon microdots of hyaluronan in the PICSI Sperm Selection Device (Biocoat, Inc., Horsham, PA) and overlaid with oil. Following a 5-10 min incubation period, HB sperm were selected following the manufacturer’s instructions	The final sperm suspension of patients in the control group was placed into standard ICSI dishes for selection

PVP: Polyvinylpyrrolidone; ICSI: Intracytoplasmic sperm injection; HA: Hyaluronic acid.