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Comparison and outcomes of nonobstructive azoospermia patients with different etiology undergoing MicroTESE and ICSI treatments.

Background
The purpose of the study was to compare clinical, laboratory, histological features, microdissection testicular sperm extraction (MicroTESE) and intracytoplasmic sperm injection (ICSI) treatment outcomes of nonobstructive azoospermia (NOA) patients of various etiologies, and to investigate ICSI outcomes using fresh and frozen thawed sperms from MicroTESE, so to explore an optimal MicroTESE-ICSI procedure for NOA couples.


Methods
A retrospective analysis was made in 595 NOA patients undergoing MicroTESE from January 2013 to December 2017. The men were classified into six groups based on etiology. Patients' age, history, hormone profile, testis volume, testicular histology, sperm retrieval, fertile and pregnancy outcomes of ICSI were included for analysis.


Results
A total of 595 NOA patients were included in this study, with 446 (75.0%) were idiopathic NOA, 66 (11.1%) were Klinefelter syndrome (KS), 34 (5.7%) with microdeletion of the AZFc, 33 (5.5%) cases had the history of cryptorchidism, 13 (2.2%) had a history of mumps orchitis, and 3 (0.5%) cases underwent chemotherapy. The overall sperm retrieval rate (SRR) was 40.3% (240/595), SRR of the cryptorchidism (84.8%, 28/33) and mumps orchitis (84.6%, 11/13) groups were much higher than that of other groups, the SRR of idiopathic group was the lowest (31.8%, 142/446). One hundred and ninety-eight ICSI cycles utilizing MicroTESE sperm were retrospectively analyzed, including 155 fresh MicroTESE ICSI cycles and 43 frozen-thawed MicroTESE ICSI cycles. Fertilization rate, cleavage rate, and clinical pregnancy rate of fresh sperm group were slightly higher than those in frozen thawed MicroTESE sperm group, but high qualified embryo rate of fresh sperm group was lower than frozen thawed group. The differences were of no statistical meaning.


Conclusions
Etiology may be an effective prognostic factor for SRR in NOA patients. NOA of definite etiology, such as cryptorchidism, has high SRR, while idiopathic NOA, the most common type of NOA, has the lowest SRR. Using of frozen thawed sperm from MicroTESE had similar pregnant outcome to that of fresh sperm, so cryopreservation of testicular sperm seems to be more suitable and of great benefit in these cases and good results can also be expected when oocyte retrieval and ICSI are not performed at the same time.