Table 4.

Clinical outcomes of different methods for viable sperm recovery by TESE. NS: no significant.

Method	Comparison	Results	Refs.
HOST	Sperm morphology	Significantly higher fertilization 43.6% vs. 28.2%, pregnancy 27.3% vs. 5.7% and ongoing pregnancy 20.5% vs. 2.9%.	[79]
	Testicular vs. ejaculated spermatozoa	Fertilization 30.1% vs. 42.7% (NS), pregnancy 16.7% vs. 13.3% (NS) and delivery/ongoing pregnancy 8.3% vs. 6.7% (NS), respectively.	[80]
Sperm tail flexibility test	Motile vs. immotile sperm selected by the test	In frozen-thawed samples; fertilization 74.3% vs. 65.7%, and pregnancies three vs. two, respectively (NS). In fresh samples; fertilization 64.4% vs. 73.4%, and pregnancies nine vs. three, respectively (NS).	[94]
Laser-assisted sperm selection	Random sperm selection	Higher fertilization 45.4% vs. 20.4% p < 0.0001, cleavage 64.4% vs. 30.6% p < 0.0001, and take-home-baby rate 9.0% vs. 5.9%.	[103]
Sperm birefringence	Normal motility/morphology	Improved grade I/II embryo 71.2% vs. 63.4% and pregnancy 46.6% vs. 33.3%, respectively.	[107]
	Routine sperm selection	Improved pregnancy 58% vs. 18% p = 0.053, implantation 42.1% vs. 12.5% p = 0.049 and ongoing pregnancy 58% vs. 9% p = 0.018, respectively.	[108]
Microfluidics-assisted sperm sorting	Standard sample processing	Improved sperm yield 13.5 sperm per min vs. 1.52 sperm per min.	[113]
Fluorescence-activated cell sorting	Standard sample processing	Improved sperm recovery 50% vs. 38%, respectively.	[121]