Successful Sperm Retrieval and Clinical Pregnancies Following Micro-TESE and ICSI Treatments in Patients with Nonobstructive Azoospermia Due to Various Etiologies

(1) Background: Nonobstructive azoospermia (NOA) etiologies affect the sperm retrieval rate (SRR) by microdissection testicular sperm extraction (micro-TESE) and the clinical outcomes following intracytoplasmic sperm injection (ICSI); (2) Methods: We investigated seven NOA etiologies. The SRR and clinical outcomes of 627 patients were analyzed between November 2017 and July 2022 in the Reproductive and Genetic Hospital of China International Trust and Investment Corporation-Xiangya (CITIC-Xiangya); (3) Results: The overall SRR was 39.4% (247/627). The SRR according to NOA etiologies were: Y chromosome azoospermia factor c microdeletions (26/46, 56.5%), Klinefelter syndrome (KS), 36/85, 42.4%), idiopathic (110/398, 27.6%), cryptorchidism (20/29, 69.0%), chromosome anomalies (7/13, 53.9%), orchitis (45/50, 90.0%), and cancer (3/6, 50.0%). The SRR were different for spermatogonia arrest (26/96, 27.1%), maturation arrest (76/177, 42.9%), and SCOS (30/80, 37.5%) according to histological examinations. The clinical pregnancy rate was similar among the NOA etiologies. The high-quality embryo rate differed between successful (54.7%) and unsuccessful (40.9%) pregnancies. Moreover, the successfully pregnant women (28.99 years) were younger than the unsuccessfully pregnant ones (30.92 years); (4) Conclusions: The SRR from patients with NOA was associated with the etiology and histological categories, while the clinical outcome was associated with the high-quality embryo rate and the female partner's age.